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Purpose: The main purpose of the study is to investigate whether the presence of residual hearing before cochlear implantation has an effect on temporal pattern recognition skills and musical perception in adults., Method: The study included adults with cochlear implants who were between the ages of 20 and 45 years. Adults with cochlear implants were divided into two groups: absent ( n = 20) and available ( n = 20) groups according to residual hearing before implantation. Frequency Pattern and Duration Pattern tests were applied to evaluate temporal pattern recognition, and the "Music-Related Quality of Life Questionnaire" was applied to evaluate musical perceptions., Results: There were no statistically significant differences between the groups in terms of cochlear-implanted hearing thresholds and speech recognition scores, musical perception, and musical activities, according to their residual hearing. On the other hand, the frequency and duration pattern recognition skills were statistically significantly better in adults with residual hearing. Also, statistically significant correlations were obtained in terms of temporal skills and musical perception subskills., Conclusions: The presence of residual hearing before cochlear implantation may affect temporal auditory processing skills. It is concluded that the integration of cochlear implants may affect temporal processing skills in adults as well as quality of life. It is recommended that experts be aware of this issue and pay attention to residual hearing.

Unilateral deafness will lead to the decline of children's speech recognition rate, language development retardation and spatial positioning ability, which will have many adverse effects on children's life and study. Cochlear implantation can help children rebuild binaural hearing, and systematic audiological evaluation after operation is particularly important for clinicians to evaluate the hearing recovery of children. In this study, a variety of commonly used audiological evaluation, testing processes and methods after cochlear implantation in children with unilateral deafness are described in detail, and the related research status and results are summarized., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Over the last decades, cognitive neuroscience has identified a distributed set of brain regions that are critical for attention. Strong anatomical overlap with brain regions critical for oculomotor processes suggests a joint network for attention and eye movements. However, the role of this shared network in complex, naturalistic environments remains understudied. Here, we investigated eye movements in relation to (un)attended sentences of natural speech. Combining simultaneously recorded eye tracking and magnetoencephalographic data with temporal response functions, we show that gaze tracks attended speech, a phenomenon we termed ocular speech tracking. Ocular speech tracking even differentiates a target from a distractor in a multi-speaker context and is further related to intelligibility. Moreover, we provide evidence for its contribution to neural differences in speech processing, emphasizing the necessity to consider oculomotor activity in future research and in the interpretation of neural differences in auditory cognition., (© 2024. The Author(s).)

Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing (DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateral and bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamental executive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differences in brain functioning regarding the impact of monaural and binaural listening in CIs compared with normal hearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditory and visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker pattern differences in visual and auditory VWM performances in CIs compared to NH peers and possible differences between unilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differences in theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivation of theta in the frontal area during the most complex condition of the auditory task and a correlation of the same activation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemisphere when compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the latter two, a correlation was found between left hemispheric gamma oscillation and performance in the audio task. These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditory VWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmark for NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targeted approach, the diagnosis and rehabilitation of VWM in DHH children., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective. Spatial auditory attention decoding (Sp-AAD) refers to the task of identifying the direction of the speaker to which a person is attending in a multi-talker setting, based on the listener's neural recordings, e.g. electroencephalography (EEG). The goal of this study is to thoroughly investigate potential biases when training such Sp-AAD decoders on EEG data, particularly eye-gaze biases and latent trial-dependent confounds, which may result in Sp-AAD models that decode eye-gaze or trial-specific fingerprints rather than spatial auditory attention. Approach. We designed a two-speaker audiovisual Sp-AAD protocol in which the spatial auditory and visual attention were enforced to be either congruent or incongruent, and we recorded EEG data from sixteen participants undergoing several trials recorded at distinct timepoints. We trained a simple linear model for Sp-AAD based on common spatial patterns filters in combination with either linear discriminant analysis (LDA) or k-means clustering, and evaluated them both across- and within-trial. Main results. We found that even a simple linear Sp-AAD model is susceptible to overfitting to confounding signal patterns such as eye-gaze and trial fingerprints (e.g. due to feature shifts across trials), resulting in artificially high decoding accuracies. Furthermore, we found that changes in the EEG signal statistics across trials deteriorate the trial generalization of the classifier, even when the latter is retrained on the test trial with an unsupervised algorithm. Significance. Collectively, our findings confirm that there exist subtle biases and confounds that can strongly interfere with the decoding of spatial auditory attention from EEG. It is expected that more complicated non-linear models based on deep neural networks, which are often used for Sp-AAD, are even more vulnerable to such biases. Future work should perform experiments and model evaluations that avoid and/or control for such biases in Sp-AAD tasks., (© 2024 IOP Publishing Ltd.)

Objectives: Children with self-limited epilepsy with centrotemporal spikes (SeLECTS) exhibit difficulty processing spoken messages without hearing loss. The temporal envelope and fine structure processing abilities are the fundamental aspects of the normal listening process. There is limited literature on the temporal envelope and fine structure processing in children with SeLECTS. We evaluated the temporal envelope and fine structure processing in children with SeLECTS., Design: The study included 35 children with SeLECTS and 50 typically developing children (TDC). The temporal envelope processing was measured using the temporal modulation transfer function (TMTF) and temporal fine structure using the temporal fine structure low-frequency (TFS LF) test. The TMTF was measured for the modulation rates 4, 8, 16, 32, 64 and 128 Hz. The TFS LF was done for 250, 500 and 750 Hz., Results: The difference in modulation detection thresholds at 4 Hz was not found to be significant, whereas there was a significant difference in modulation detection thresholds observed for all the other modulation frequencies (p < 0.05) between the children with SeLECTS and TDC. The thresholds at 250, 500 and 750 Hz were higher (poorer) for children with SeLECTS than the TDC and was significant (p < 0.05)., Conclusions: The TMTF and TFS LF tests were of practical use in evaluating temporal envelope and fine structure processing abilities in children with SeLECTS. The results suggest that children with SeLECTS have a poor temporal envelope and fine structure processing compared to the TDC., Competing Interests: Declaration of Competing Interest There is no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Purpose: Listening-related fatigue is a potential negative consequence of challenges experienced during everyday listening and may disproportionately affect older adults. Contrary to expectation, we recently found that increased reports of listening-related fatigue were associated with better performance on a dichotic listening task. However, this link was found only in individuals who reported heightened sensitivity to a variety of physical, social, and emotional stimuli (i.e., increased "sensory-processing sensitivity" [SPS]). This study examined whether perceived effort may underlie the link between performance and fatigue., Method: Two hundred six young adults, aged 18-30 years (Experiment 1), and 122 older adults, aged 60-80 years (Experiment 2), performed a dichotic listening task and were administered a series of questionnaires including the NASA Task Load Index of perceived effort, the Vanderbilt Fatigue Scale (measuring daily life listening-related fatigue), and the Highly Sensitive Person Scale (measuring SPS). Both experiments were completed online., Results: SPS predicted listening-related fatigue, but perceived effort during the listening task was not associated with SPS or listening-related fatigue in either age group. We were also unable to replicate the interaction between dichotic listening performance and SPS in either group. Exploratory analyses revealed contrasting effects of age; older adults found the dichotic listening task more effortful but indicated lower overall fatigue., Conclusions: These findings suggest that SPS is a better predictor of listening-related fatigue than performance or effort ratings on a dichotic listening task. SPS may be an important factor in determining an individual's likelihood of experiencing listening-related fatigue irrespective of hearing or cognitive ability., Supplemental Material: https://doi.org/10.23641/asha.21893013.

The goal of auditory attention decoding (AAD) is to determine to which speaker out of multiple competing speakers a listener is attending based on the brain signals recorded via, e.g., electroencephalography (EEG). AAD algorithms are a fundamental building block of so-called neuro-steered hearing devices that would allow identifying the speaker that should be amplified based on the brain activity. A common approach is to train a subject-specific stimulus decoder that reconstructs the amplitude envelope of the attended speech signal. However, training this decoder requires a dedicated 'ground-truth' EEG recording of the subject under test, during which the attended speaker is known. Furthermore, this decoder remains fixed during operation and can thus not adapt to changing conditions and situations. Therefore, we propose an online time-adaptive unsupervised stimulus reconstruction method that continuously and automatically adapts over time when new EEG and audio data are streaming in. The adaptive decoder does not require ground-truth attention labels obtained from a training session with the end-user and instead can be initialized with a generic subject-independent decoder or even completely random values. We propose two different implementations: a sliding window and recursive implementation, which we extensively validate on three independent datasets based on multiple performance metrics. We show that the proposed time-adaptive unsupervised decoder outperforms a time-invariant supervised decoder, representing an important step toward practically applicable AAD algorithms for neuro-steered hearing devices.

Many natural events generate both visual and auditory signals, and humans are remarkably adept at integrating information from those sources. However, individuals appear to differ markedly in their ability or propensity to combine what they hear with what they see. Individual differences in audiovisual integration have been established using a range of materials, including speech stimuli (seeing and hearing a talker) and simpler audiovisual stimuli (seeing flashes of light combined with tones). Although there are multiple tasks in the literature that are referred to as "measures of audiovisual integration," the tasks themselves differ widely with respect to both the type of stimuli used (speech versus non-speech) and the nature of the tasks themselves (e.g., some tasks use conflicting auditory and visual stimuli whereas others use congruent stimuli). It is not clear whether these varied tasks are actually measuring the same underlying construct: audiovisual integration. This study tested the relationships among four commonly-used measures of audiovisual integration, two of which use speech stimuli (susceptibility to the McGurk effect and a measure of audiovisual benefit), and two of which use non-speech stimuli (the sound-induced flash illusion and audiovisual integration capacity). We replicated previous work showing large individual differences in each measure but found no significant correlations among any of the measures. These results suggest that tasks that are commonly referred to as measures of audiovisual integration may be tapping into different parts of the same process or different constructs entirely., (© 2022. The Psychonomic Society, Inc.)

Whilst functional neuroimaging has been used to investigate cortical processing of degraded speech in adults, much less is known about how these signals are processed in children. An enhanced understanding of cortical correlates of poor speech perception in children would be highly valuable to oral communication applications, including hearing devices. We utilised vocoded speech stimuli to investigate brain responses to degraded speech in 29 normally hearing children aged 6-12 years. Intelligibility of the speech stimuli was altered in two ways by (i) reducing the number of spectral channels and (ii) reducing the amplitude modulation depth of the signal. A total of five different noise-vocoded conditions (with zero, partial or high intelligibility) were presented in an event-related format whilst participants underwent functional near-infrared spectroscopy (fNIRS) neuroimaging. Participants completed a word recognition task during imaging, as well as a separate behavioural speech perception assessment. fNIRS recordings revealed statistically significant sensitivity to stimulus intelligibility across several brain regions. More intelligible stimuli elicited stronger responses in temporal regions, predominantly within the left hemisphere, while right inferior parietal regions showed an opposite, negative relationship. Although there was some evidence that partially intelligible stimuli elicited the strongest responses in the left inferior frontal cortex, a region previous studies have suggested is associated with effortful listening in adults, this effect did not reach statistical significance. These results further our understanding of cortical mechanisms underlying successful speech perception in children. Furthermore, fNIRS holds promise as a clinical technique to help assess speech intelligibility in paediatric populations., (© 2021. The Author(s).)

When multiple speakers talk simultaneously, a hearing device cannot identify which of these speakers the listener intends to attend to. Auditory attention decoding (AAD) algorithms can provide this information by, for example, reconstructing the attended speech envelope from electroencephalography (EEG) signals. However, these stimulus reconstruction decoders are traditionally trained in a supervised manner, requiring a dedicated training stage during which the attended speaker is known. Pre-trained subject-independent decoders alleviate the need of having such a per-user training stage but perform substantially worse than supervised subject-specific decoders that are tailored to the user. This motivates the development of a new unsupervised self-adapting training/updating procedure for a subject-specific decoder, which iteratively improves itself on unlabeled EEG data using its own predicted labels. This iterative updating procedure enables a self-leveraging effect, of which we provide a mathematical analysis that reveals the underlying mechanics. The proposed unsupervised algorithm, starting from a random decoder, results in a decoder that outperforms a supervised subject-independent decoder. Starting from a subject-independent decoder, the unsupervised algorithm even closely approximates the performance of a supervised subject-specific decoder. The developed unsupervised AAD algorithm thus combines the two advantages of a supervised subject-specific and subject-independent decoder: it approximates the performance of the former while retaining the 'plug-and-play' character of the latter. As the proposed algorithm can be used to automatically adapt to new users, as well as over time when new EEG data is being recorded, it contributes to more practical neuro-steered hearing devices.

Objectives/hypothesis: Speech recognition with a cochlear implant (CI) tends to be better for younger adults than older adults. However, older adults may take longer to reach asymptotic performance than younger adults. The present study aimed to characterize speech recognition as a function of age at implantation and listening experience for adult CI users., Study Design: Retrospective review., Methods: A retrospective review identified 352 adult CI recipients (387 ears) with at least 5 years of device listening experience. Speech recognition, as measured with consonant-nucleus-consonant (CNC) words in quiet and AzBio sentences in a 10-talker noise masker (10 dB signal-to-noise ratio), was reviewed at 1, 5, and 10 years postactivation., Results: Speech recognition was better in younger listeners, and performance was stable or continued to improve through 10 years of CI listening experience. There was no indication of differences in acclimatization as a function of age at implantation. For the better performing CI recipients, an effect of age at implantation was more apparent for sentence recognition in noise than for word recognition in quiet., Conclusions: Adult CI recipients across the age range examined here experience speech recognition benefit with a CI. However, older adults perform more poorly than young adults for speech recognition in quiet and noise, with similar age effects through 5 to 10 years of listening experience., Level of Evidence: 3 Laryngoscope, 131:2106-2111, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc..)

Objective: This study aimed to investigate the temporal processing and binaural interaction functions of central auditory processing tests according to the anatomical localizations of young and elderly individuals. It also sought to evaluate the relationships between the same individuals' central auditory processing tests., Methods: This observational and cross-sectional study included individuals with normal hearing between 18 and 30 and 60-75 years of age, who were referred to as the young group and the elderly group, respectively. The evaluation of the central auditory processing tests was completed using the frequency pattern test, duration pattern test, masking level difference test, and random gap detection test. Furthermore, speech discrimination and speech in noise scores were analyzed for both groups., Results: Statistically significant differences were identified between the groups' scores for the speech in noise test, masking level difference test, random gap detection test, frequency pattern test, and duration pattern test (p < 0.05). A statistically significant relationship was observed between the age and the results of the central auditory processing tests (p < 0.05)., Conclusion: When compared to younger individuals, elderly individuals presented with declined temporal sequences, temporal resolutions, and binaural interaction skills., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest. The authors alone are responsible for the content and writing of this article. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors., (Copyright © 2020. Published by Elsevier B.V.)

Background: In the literature, the effect of chronic kidney disease on the peripheral auditory system has been well documented. But studies investigating the effect of chronic kidney disease on speech perception and auditory processing abilities are limited., Aims/objectives: The present study investigated the effect of chronic kidney disease on different auditory processing tasks and speech perception in noise among adults., Material and Methods: A total of 28 adults participated in the study. Group 1 included 14 individuals with chronic kidney disease undergoing hemodialysis, and Group 2 included 14 individuals with no known kidney complications. Amplitude modulation detection threshold, gap detection threshold, spectral ripple discrimination threshold, and speech recognition threshold in noise were measured. Independent samples t -test was carried out to investigate whether mean thresholds are significantly different between groups., Results: Results showed poorer gap detection threshold, amplitude modulation detection threshold, spectral ripple discrimination threshold, and speech recognition threshold in noise among individuals with chronic kidney disease compared to individuals with no known kidney complications., Conclusions: The present study showed poorer auditory processing and speech perception abilities in individuals with chronic kidney disease.

Neuroscientific and clinical studies on auditory perception often use headphones to limit sound interference. In these conditions, sounds are perceived as internalized because they lack the sound-attributes that normally occur with a sound produced from a point in space around the listener. Without the spatial attention mechanisms that occur with localized sounds, auditory functional assessments could thus be underestimated. We hypothesize that adding virtually externalization and localization cues to sounds through headphones enhance sound discrimination in both healthy participants and patients with a disorder of consciousness (DOC). Hd-EEG was analyzed in 14 healthy participants and 18 patients while they listened to self-relevant and irrelevant stimuli in two forms: diotic (classic sound presentation with an "internalized" feeling) and convolved with a binaural room impulse response (to create an "externalized" feeling). Convolution enhanced the brains' discriminative response as well as the processing of irrelevant sounds itself, in both healthy participants and DOC patients. For the healthy participants, these effects could be associated with enhanced activation of both the dorsal (where/how) and ventral (what) auditory streams, suggesting that spatial attributes support speech discrimination. Thus, virtually spatialized sounds might "call attention to the outside world" and improve the sensitivity of assessment of brain function in DOC patients.

Nicolelis wrote in his 2003 review on brain-machine interfaces (BMIs) that the design of a successful BMI relies on general physiological principles describing how neuronal signals are encoded. Our study explored whether neural information exchanged between brains of different species is possible, similar to the information exchange between computers. We show for the first time that single words processed by the guinea pig auditory system are intelligible to humans who receive the processed information via a cochlear implant. We recorded the neural response patterns to single-spoken words with multi-channel electrodes from the guinea inferior colliculus. The recordings served as a blueprint for trains of biphasic, charge-balanced electrical pulses, which a cochlear implant delivered to the cochlear implant user's ear. Study participants completed a four-word forced-choice test and identified the correct word in 34.8% of trials. The participants' recognition, defined by the ability to choose the same word twice, whether right or wrong, was 53.6%. For all sessions, the participants received no training and no feedback. The results show that lexical information can be transmitted from an animal to a human auditory system. In the discussion, we will contemplate how learning from the animals might help developing novel coding strategies.

Multisensory input can improve perception of ambiguous unisensory information. For example, speech heard in noise can be more accurately identified when listeners see a speaker's articulating face. Importantly, these multisensory effects can be superadditive to listeners' ability to process unisensory speech, such that audiovisual speech identification is better than the sum of auditory-only and visual-only speech identification. Age-related declines in auditory and visual speech perception have been hypothesized to be concomitant with stronger cross-sensory influences on audiovisual speech identification, but little evidence exists to support this. Currently, studies do not account for the multisensory superadditive benefit of auditory-visual input in their metrics of the auditory or visual influence on audiovisual speech perception. Here we treat multisensory superadditivity as independent from unisensory auditory and visual processing. In the current investigation, older and younger adults identified auditory, visual, and audiovisual speech in noisy listening conditions. Performance across these conditions was used to compute conventional metrics of the auditory and visual influence on audiovisual speech identification and a metric of auditory-visual superadditivity. Consistent with past work, auditory and visual speech identification declined with age, audiovisual speech identification was preserved, and no age-related differences in the auditory or visual influence on audiovisual speech identification were observed. However, we found that auditory-visual superadditivity improved with age. The novel findings suggest that multisensory superadditivity is independent of unisensory processing. As auditory and visual speech identification decline with age, compensatory changes in multisensory superadditivity may preserve audiovisual speech identification in older adults. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Objective: Noise reduction algorithms in current hearing devices lack informationabout the sound source a user attends to when multiple sources are present. To resolve this issue, they can be complemented with auditory attention decoding (AAD) algorithms, which decode the attention using electroencephalography (EEG) sensors. State-of-the-art AAD algorithms employ a stimulus reconstruction approach, in which the envelope of the attended source is reconstructed from the EEG and correlated with the envelopes of the individual sources. This approach, however, performs poorly on short signal segments, whilelonger segments yield impractically long detection delays when the user switches attention., Methods: We propose decoding the directional focus of attention using filterbank common spatial pattern filters (FB-CSP) as an alternative AAD paradigm, whichdoes not require access to the clean source envelopes., Results: The proposed FB-CSP approach outperforms both the stimulus reconstruction approach on short signal segments, as well as a convolutional neural network approach on the same task. We achieve a high accuracy (80% for [Formula: see text] windows and 70% for quasi-instantaneous decisions), which is sufficient to reach minimal expected switch durations below [Formula: see text]. We also demonstrate that the decoder can adapt to unlabeled data from anunseen subject and works with only a subset of EEG channels located around the ear to emulate a wearable EEG setup., Conclusion: The proposed FB-CSP method provides fast and accurate decoding of the directional focus of auditory attention., Significance: The high accuracy on very short data segments is a major step forward towards practical neuro-steered hearing devices.

Brain connectivity plays a major role in the encoding, transfer, and integration of sensory information. Interregional synchronization of neural oscillations in the γ-frequency band has been suggested as a key mechanism underlying perceptual integration. In a recent study, we found evidence for this hypothesis showing that the modulation of interhemispheric oscillatory synchrony by means of bihemispheric high-density transcranial alternating current stimulation (HD-TACS) affects binaural integration of dichotic acoustic features. Here, we aimed to establish a direct link between oscillatory synchrony, effective brain connectivity, and binaural integration. We experimentally manipulated oscillatory synchrony (using bihemispheric γ-TACS with different interhemispheric phase lags) and assessed the effect on effective brain connectivity and binaural integration (as measured with functional MRI and a dichotic listening task, respectively). We found that TACS reduced intrahemispheric connectivity within the auditory cortices and antiphase (interhemispheric phase lag 180°) TACS modulated connectivity between the two auditory cortices. Importantly, the changes in intra- and interhemispheric connectivity induced by TACS were correlated with changes in perceptual integration. Our results indicate that γ-band synchronization between the two auditory cortices plays a functional role in binaural integration, supporting the proposed role of interregional oscillatory synchrony in perceptual integration., Competing Interests: The authors declare no competing interest.

It has become widely accepted that humans use contextual information to infer the meaning of ambiguous acoustic signals. In speech, for example, high-level semantic, syntactic, or lexical information shape our understanding of a phoneme buried in noise. Most current theories to explain this phenomenon rely on hierarchical predictive coding models involving a set of Bayesian priors emanating from high-level brain regions (e.g., prefrontal cortex) that are used to influence processing at lower-levels of the cortical sensory hierarchy (e.g., auditory cortex). As such, virtually all proposed models to explain top-down facilitation are focused on intracortical connections, and consequently, subcortical nuclei have scarcely been discussed in this context. However, subcortical auditory nuclei receive massive, heterogeneous, and cascading descending projections at every level of the sensory hierarchy, and activation of these systems has been shown to improve speech recognition. It is not yet clear whether or how top-down modulation to resolve ambiguous sounds calls upon these corticofugal projections. Here, we review the literature on top-down modulation in the auditory system, primarily focused on humans and cortical imaging/recording methods, and attempt to relate these findings to a growing animal literature, which has primarily been focused on corticofugal projections. We argue that corticofugal pathways contain the requisite circuitry to implement predictive coding mechanisms to facilitate perception of complex sounds and that top-down modulation at early (i.e., subcortical) stages of processing complement modulation at later (i.e., cortical) stages of processing. Finally, we suggest experimental approaches for future studies on this topic., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Asilador and Llano.)

Objective: Long-term outcomes of early implanted, young adult cochlear implant (CI) users remain variable. We measured auditory discrimination by means of event-related potentials in this population to examine whether variability at the level of cortical auditory processing helps to explain speech abilities., Methods: Using an auditory oddball paradigm, the P300 and Mismatch Negativity (MMN) were measured in 8 young adult CI users and 14 normal-hearing peers. We related P300 amplitude and latency to clinical speech perception scores in quiet and to duration of deafness., Results: All individuals showed P300 responses. The MMN response was less robust in both groups. There was no evidence for differences in P300 responses between CI users and controls. P300 amplitude was associated with speech perception scores (r = 0.70, p = .05) and duration of deafness (r = -0.83, p = .009)., Conclusions: Early CI implantation yields good auditory processing outcomes at young adult age and, in contrast to MMN, the P300 provides a robust measure for auditory processing on an individual level., Significance: At the cortical level, early implanted, long-term CI users have good auditory discrimination, leaving variability in implantation outcomes unexplained. This group provides unique insight into the long-term neurophysiological underpinnings of early implantation., Competing Interests: Declaration of Competing Interest None of the authors have potential conflicts of interest to be disclosed. All funding resources supporting this study are acknowledged. The authors declare that the research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: The objectives of this study are to evaluate cochlear implant (CI) listeners' ability to infer low frequency (LF) pitch information from temporal fine structure (TFS) cues and to gain insight into its effects on speech perception, especially in the presence of a fluctuating background noise. Pitch perception assessment using linguistic stimuli is believed to better reflect the role of pitch in communicatively realistic situations., Methods: The low-pass-filtered sentence intonation (SI-LPF) test based on linguistic stimuli marked by intonation changes is used to estimate a difference limen for discrimination of LF pitch changes in adult CI listeners (N = 17 ears). Speech perception in the presence of noise is assessed using the sentence test with adaptive randomized roving level (STARR), where everyday sentences are presented at low, medium, and high levels in a fluctuating background noise. SI-LPF correlations with STARR are compared to those with sentence recognition tests presented in quiet (SRQ) and in noise, using fixed signal-to-noise ratio (SNRs at +10 and +5 dB)., Results: SI-LPF findings show significant positive correlations with STARR performance (r s  = 0.63, p = 0.007), whilst the associations with SRQ (r s  = - 0.37, p = 0.149), SNR + 10 (r s  = - 0.24, p = 0.345), and SNR + 5 (r s  = - 0.14, p = 0.587) are not statistically significant., Conclusions: Present findings reflecting considerably stronger correlations than previous studies using non-linguistic stimuli, in particular for speech perception with roving-level adaptive test method (STARR) highlight the effects of LF pitch perception and TFS sensitivity on challenging everyday situations, where CI users listen to speakers with varying levels in a fluctuating background.

Males and females differ in their subcortical evoked responses to sound. For many evoked response measures, the sex difference is driven by a faster developmental decline of auditory processing in males. Using the frequency-following response (FFR), an evoked potential that reflects predominately midbrain processing of stimulus features, sex differences were identified in the response to the temporal envelope of speech. The pattern of later and smaller responses in males versus females is consistent with two of the three response features that track with language development and reading abilities. Therefore, here we analyzed subcortical response consistency, the third distinguishing feature of language ability. Furthermore, though the envelope is primarily a low-frequency response, the greatest sex differences were observed in harmonics encoding. To better understand these sex differences, we extended these findings to the temporal fine structure response, which is biased to high-frequency information. Using the same 516 participants as previously reported (Krizman et al., 2019), we analyzed the effect of sex across development on response consistency and the encoding of temporal fine structure, as indexed by the subtracted frequency-following response. We found that while males and females did not differ on response consistency, there was an effect of age on this measure. Moreover, while males still showed a faster decline in harmonic encoding, the magnitude and breadth of the sex differences were smaller (accounting for 2% variance) in the temporal fine structure response compared to the envelope response. These results suggest that sex differences are distinct, at least in part, from the differences that underlie language abilities and that developmental sex differences reflect subcortical auditory processing differences of both the temporal envelope and fine structure of sounds., (Copyright © 2020. Published by Elsevier B.V.)

A longstanding focus of perceptual learning research is learning specificity, the difficulty for learning to transfer to tasks and situations beyond the training setting. Previous studies have focused on promoting transfer across stimuli, such as from one sound frequency to another. Here we examined whether learning could transfer across tasks, particularly from fine discrimination of sound features to speech perception in noise, one of the most frequently encountered perceptual challenges in real life. Separate groups of normal-hearing listeners were trained on auditory interaural level difference (ILD) discrimination, interaural time difference (ITD) discrimination, and fundamental frequency (F 0 ) discrimination with non-speech stimuli delivered through headphones. While ITD training led to no improvement, both ILD and F 0 training produced learning as well as transfer to speech-in-noise perception when noise differed from speech in the trained feature. These training benefits did not require similarity of task or stimuli between training and application settings, construing far and wide transfer. Thus, notwithstanding task specificity among basic perceptual skills such as discrimination of different sound features, auditory learning appears readily transferable between these skills and their "upstream" tasks utilizing them, providing an effective approach to improving performance in challenging situations or challenged populations.

Perception necessitates interaction among neuronal ensembles, the dynamics of which can be conceptualized as the emergent behavior of coupled dynamical systems. Here, we propose a detailed neurobiologically realistic model that captures the neural mechanisms of inter-individual variability observed in cross-modal speech perception. From raw EEG signals recorded from human participants when they were presented with speech vocalizations of McGurk-incongruent and congruent audio-visual (AV) stimuli, we computed the global coherence metric to capture the neural variability of large-scale networks. We identified that participants' McGurk susceptibility was negatively correlated to their alpha band global coherence. The proposed biophysical model conceptualized the global coherence dynamics emerge from coupling between the interacting neural masses-representing the sensory-specific auditory/visual areas and modality nonspecific associative/integrative regions. Subsequently, we could predict that an extremely weak direct AV coupling results in a decrease in alpha band global coherence-mimicking the cortical dynamics of participants with higher McGurk susceptibility. Source connectivity analysis also showed decreased connectivity between sensory-specific regions in participants more susceptible to McGurk effect, thus establishing an empirical validation to the prediction. Overall, our study provides an outline to link variability in structural and functional connectivity metrics to variability of performance that can be useful for several perception and action task paradigms., (© 2020 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Purpose Cochlear implant (CI) performance varies considerably across individuals and across domains of auditory function, but clinical testing is typically restricted to speech intelligibility. The goals of this study were (a) to develop a basic auditory skills evaluation battery of tests for comprehensive assessment of ecologically relevant aspects of auditory perception and (b) to compare CI listeners' performance on the battery when tested in the laboratory by an audiologist or independently at home. Method The battery included 17 tests to evaluate (a) basic spectrotemporal processing, (b) processing of music and environmental sounds, and (c) speech perception in both quiet and background noise. The battery was administered online to three groups of adult listeners: two groups of postlingual CI listeners and a group of older normal-hearing (ONH) listeners of similar age. The ONH group and one CI group were tested in a laboratory by an audiologist, whereas the other CI group self-tested independently at home following online instructions. Results Results indicated a wide range in the performance of CI but not ONH listeners. Significant differences were not found between the two CI groups on any test, whereas on all but two tests, CI listeners' performance was lower than that of the ONH participants. Principal component analysis revealed that four components accounted for 82% of the variance in measured results, with component loading indicating that the test battery successfully captures differences across dimensions of auditory perception. Conclusions These results provide initial support for the use of the basic auditory skills evaluation battery for comprehensive online assessment of auditory skills in adult CI listeners.

Verbal communication often takes place in situations with several simultaneous speakers ("cocktail party listening"). These situations can be static (only one listening target) or dynamic (with alternating targets). In particular, dynamic cocktail party listening is believed to generate extra cognitive load and appears to be particularly demanding for older listeners. Two groups of younger and older listeners with good hearing and normal cognition participated in the present study. Three different, spatially separated talker voices uttering matrix sentences were presented to each listener with varying types and probabilities of target switches. Moreover, several neuropsychological tests were conducted to investigate general cognitive characteristics that may be important for speech understanding in these situations. In a static condition with a priori knowledge of the target talker, both age groups revealed very high speech recognition performance. In comparison, dynamic conditions caused extra costs associated with the need to monitor different potential sound sources and to refocus attention when the target changed. The amount of costs depended on the probability and type of target talker alterations. Again, no significant age-group differences were found. No significant associations of cognitive characteristics and costs could be shown. However, a more fine-grained analysis based on the calculation of general and specific switch costs showed different mechanisms in older and younger listeners. This study confirms that dynamic cocktail party listening is associated with costs that depend on the type and probability of target switches. It extends previous research by showing that the effects of switching type and probability are similar for younger and older listeners with good hearing and good cognitive abilities. It further shows that, despite comparable costs of dynamic listening, mechanisms are different for the two age groups, as switching auditory attention may be preserved with aging, but monitoring different sound sources appears to be more difficult for older adults., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Language-related change-detection processes are often investigated using syllables that are very simple in terms of phonological structure. However, phonological complexity is known to be challenging for young typically developing children and pathological populations. We investigated brain correlates of phonological processing and their age-related changes with a passive change-detection protocol including stimuli of varying phonological complexity, which allowed comparing responses to simple and complex phonological deviancies. Mismatch Negativity (MMN) and Late Discriminative Negativity (LDN) responses were recorded in both school-age children (n = 22) and adults (n = 24). MMN was similar for simple and complex phonological deviancy in both groups, whereas LDN appeared to be modulated by phonological complexity, albeit with different patterns according to age. In response to complex phonological change, children displayed a larger LDN response with a typical fronto-central scalp distribution, while adults showed an additional right-posterior activity but no larger amplitude than for simple change. Thus, LDN appears to be a good electrophysiological index of phonological complexity processing. This study validated the use of the LDN through this protocol for the investigation of phonological complexity processing throughout the development., (© 2020 Society for Psychophysiological Research.)

Tinnitus is a sound heard by 15% of the general population in the absence of any external sound. Because external sounds can sometimes mask tinnitus, tinnitus is assumed to affect the perception of external sounds, leading to hypotheses such as "tinnitus filling in the temporal gap" in animal models and "tinnitus inducing hearing difficulty" in human subjects. Here we compared performance in temporal, spectral, intensive, masking and speech-in-noise perception tasks between 45 human listeners with chronic tinnitus (18 females and 27 males with a range of ages and degrees of hearing loss) and 27 young, normal-hearing listeners without tinnitus (11 females and 16 males). After controlling for age, hearing loss, and stimulus variables, we discovered that, contradictory to the widely held assumption, tinnitus does not interfere with the perception of external sounds in 32 of the 36 measures. We interpret the present result to reflect a bottom-up pathway for the external sound and a separate top-down pathway for tinnitus. We propose that these two perceptual pathways can be independently modulated by attention, which leads to the asymmetrical interaction between external and internal sounds, and several other puzzling tinnitus phenomena such as discrepancy in loudness between tinnitus rating and matching. The present results suggest not only a need for new theories involving attention and central noise in animal tinnitus models but also a shift in focus from treating tinnitus to managing its comorbid conditions when addressing complaints about hearing difficulty in individuals with tinnitus. SIGNIFICANCE STATEMENT Tinnitus, or ringing in the ears, is a neurologic disorder that affects 15% of the general population. Here we discovered an asymmetrical relationship between tinnitus and external sounds: although external sounds have been widely used to cover up tinnitus, tinnitus does not impair, and sometimes even improves, the perception of external sounds. This counterintuitive discovery contradicts the general belief held by scientists, clinicians, and even individuals with tinnitus themselves, who often report hearing difficulty, especially in noise. We attribute the counterintuitive discovery to two independent pathways: the bottom-up perception of external sounds and the top-down perception of tinnitus. Clinically, the present work suggests a shift in focus from treating tinnitus itself to treating its comorbid conditions and secondary effects., (Copyright © 2020 the authors.)

Understanding how the human brain processes auditory input remains a challenge. Traditionally, a distinction between lower- and higher-level sound features is made, but their definition depends on a specific theoretical framework and might not match the neural representation of sound. Here, we postulate that constructing a data-driven neural model of auditory perception, with a minimum of theoretical assumptions about the relevant sound features, could provide an alternative approach and possibly a better match to the neural responses. We collected electrocorticography recordings from six patients who watched a long-duration feature film. The raw movie soundtrack was used to train an artificial neural network model to predict the associated neural responses. The model achieved high prediction accuracy and generalized well to a second dataset, where new participants watched a different film. The extracted bottom-up features captured acoustic properties that were specific to the type of sound and were associated with various response latency profiles and distinct cortical distributions. Specifically, several features encoded speech-related acoustic properties with some features exhibiting shorter latency profiles (associated with responses in posterior perisylvian cortex) and others exhibiting longer latency profiles (associated with responses in anterior perisylvian cortex). Our results support and extend the current view on speech perception by demonstrating the presence of temporal hierarchies in the perisylvian cortex and involvement of cortical sites outside of this region during audiovisual speech perception., Competing Interests: The authors have declared that no competing interests exist.

Informational masking emerges with processing of complex sounds in the central auditory system and can be affected by uncertainty emerging from trial-to-trial variation of stimulus features. Uncertainty can be non-informative but confusing and thus mask otherwise salient stimulus changes resulting in increased discrimination thresholds. With increasing age, the ability for processing of such complex sound scenes degrades. Here, 6 young and 4 old gerbils were tested behaviorally in a vowel discrimination task. Animals were trained to discriminate between sequentially presented target and reference vowels of the vowel pair/I/-/i/. Reference and target vowels were generated shifting the three formants of the reference vowel in steps towards the formants of the target vowels. Non-informative but distracting uncertainty was introduced by random changes in location, level, fundamental frequency or all three features combined. Young gerbils tested with uncertainty for the target or target and reference vowels showed similar informational masking effects for both conditions. Young and old gerbils were tested with uncertainty for the target vowels only. Old gerbils showed no threshold increase discriminating vowels without uncertainty in comparison with young gerbils. Introducing uncertainty, vowel discrimination thresholds increased for young and old gerbils and vowel discrimination thresholds increased most when presenting all three uncertainty features combined. Old gerbils were more susceptible to non-informative uncertainty and their thresholds increased more than thresholds of young gerbils. Gerbils' vowel discrimination thresholds are compared to human performance in the same task (Eipert et al., 2019)., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: The main purpose of the current study was to assess the development of auditory and speech perception and the effects of the age at implantation in CI children after long-period follow up., Materials and Methods: Five hundred and forty-four young children participated in this study (339 males and 205 females). The age at implantation ranged from 6 months to 36 months. All subjects were prelingually bilateral profound sensorineural hearing loss. They were divided into 3 groups according to the implant ages: group 1 (age at implantation < 12 months, n = 109); group 2 (12 months < age at implantation < 24 months, n = 284); and group 3 (24 months < age at implantation < 36 months, n = 151). The categorical auditory performance (CAP) was used to assess auditory abilities and the speech intelligibility rating (SIR) was used to assess the speech intelligibility of these CI children. The tests were administered at pre-surgery and 1, 3, 6, 12, 24, 36, 48- and 60-months post-surgery., Results: All the subjects demonstrated improvements of auditory abilities and speech intelligibility after CI surgery. The auditory ability developed quickly in 12 months after implantation. However, the speech intelligibility scores show rapid improvement within 24 months post implantation. Significant difference was found between group 1 and group 3, group 2 and group 3 before 12 months post-implantation for CAP and SIR. The three groups of children showed similar development pattern for their auditory abilities and speech intelligibility., Conclusion: The results of this study suggested dramatic and continuous improvement of the auditory and speech abilities post implantation in these CI children. Furthermore, the age at implantation played a considerably smaller role in the improvement of hearing and speech abilities. However, earlier implantation still benefits the language development., Competing Interests: Declaration of competing interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Perception of sounds occurs in the context of surrounding sounds. When spectral properties differ between earlier (context) and later (target) sounds, categorization of later sounds becomes biased through spectral contrast effects (SCEs). Past research has shown SCEs to bias categorization of speech and music alike. Recent studies have extended SCEs to naturalistic listening conditions when the inherent spectral composition of (unfiltered) sentences biased speech categorization. Here, we tested whether natural (unfiltered) music would similarly bias categorization of French horn and tenor saxophone targets. Preceding contexts were either solo performances of the French horn or tenor saxophone (unfiltered; 1 second duration in Experiment 1, or 3 seconds duration in Experiment 2) or a string quintet processed to emphasize frequencies in the horn or saxophone (filtered; 1 second duration). Both approaches produced SCEs, producing more "saxophone" responses following horn / horn-like contexts and vice versa. One-second filtered contexts produced SCEs as in previous studies, but 1-second unfiltered contexts did not. Three-second unfiltered contexts biased perception, but to a lesser degree than filtered contexts did. These results extend SCEs in musical instrument categorization to everyday listening conditions.

Individuals diagnosed with autism spectrum disorder (ASD) have difficulty perceiving and expressing emotions. Since prosodic changes in speech (i.e. changes in intonation, stress, rhythm, etc.) are crucial for extracting information about the emotional state of a speaker, an inability to perceive and interpret these prosodic changes may be related to impairments in social communication. This study used non-verbal emotional voice-clips to examine the ability of autistic and typically-developing children (7-13 years old) to extract affect from changes in prosody. This research also explored whether difficulty extracting affective intent from changes in prosody may be related to social competence. Autistic (n = 26) and typically-developing (n = 26) children accurately matched emotional voice-clips to emotion words, suggesting autistic children can accurately extract the affective meaning conveyed by changes in prosody. Autistic children were less accurate at matching the voice-clips to emotional faces, suggesting that autistic children may struggle to make use of prosodic information in a social context. Across both autistic and typically-developing children, prosody-face matching accuracy was found to predict overall social competence, as well as social inferencing abilities, suggesting that the inability to utilize affective information derived from a speaker's voice may interfere with effective social communication.

Auditory cortex (AC) is necessary for the detection of brief gaps in ongoing sounds, but not for the detection of longer gaps or other stimuli such as tones or noise. It remains unclear why this is so, and what is special about brief gaps in particular. Here, we used both optogenetic suppression and conventional lesions to show that the cortical dependence of brief gap detection hinges specifically on gap termination. We then identified a cortico-collicular gap detection circuit that amplifies cortical gap termination responses before projecting to inferior colliculus (IC) to impact behavior. We found that gaps evoked off-responses and on-responses in cortical neurons, which temporally overlapped for brief gaps, but not long gaps. This overlap specifically enhanced cortical responses to brief gaps, whereas IC neurons preferred longer gaps. Optogenetic suppression of AC reduced collicular responses specifically to brief gaps, indicating that under normal conditions, the enhanced cortical representation of brief gaps amplifies collicular gap responses. Together these mechanisms explain how and why AC contributes to the behavioral detection of brief gaps, which are critical cues for speech perception, perceptual grouping, and auditory scene analysis., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

To adapt to situations in which speech perception is difficult, listeners can adjust boundaries between phoneme categories using perceptual learning. Such adjustments can draw on lexical information in surrounding speech, or on visual cues via speech-reading. In the present study, listeners proved they were able to flexibly adjust the boundary between two plosive/stop consonants, /p/-/t/, using both lexical and speech-reading information and given the same experimental design for both cue types. Videos of a speaker pronouncing pseudo-words and audio recordings of Dutch words were presented in alternating blocks of either stimulus type. Listeners were able to switch between cues to adjust phoneme boundaries, and resulting effects were comparable to results from listeners receiving only a single source of information. Overall, audiovisual cues (i.e., the videos) produced the stronger effects, commensurate with their applicability for adapting to noisy environments. Lexical cues were able to induce effects with fewer exposure stimuli and a changing phoneme bias, in a design unlike most prior studies of lexical retuning. While lexical retuning effects were relatively weaker compared to audiovisual recalibration, this discrepancy could reflect how lexical retuning may be more suitable for adapting to speakers than to environments. Nonetheless, the presence of the lexical retuning effects suggests that it may be invoked at a faster rate than previously seen. In general, this technique has further illuminated the robustness of adaptability in speech perception, and offers the potential to enable further comparisons across differing forms of perceptual learning.

Background: Forward masking occurs when noise is presented before the target signal, making the latter difficult to be perceived. It is related to temporal auditory processing and consequently to speech recognition in noisy environments, which may decline with age. Interest in forward masking has grown in the last years. Studies investigate psychoacoustic and electrophysiological recordings in different age- groups., Purpose: The purpose of the study was to investigate the effect of forward masking on frequency following response (FFR) as a function of age., Research Design: Cross-sectional analytical observational study., Study Sample: We assessed 69 normal-hearing participants of both genders assigned to three groups: 40 young individuals (aged 18-25 years, mean age = 22 years 8 months), 21 middle-age individuals (aged 25-55 years, mean age = 37 years 2 months), and 8 seniors (aged <55 years, mean age = 65 years 3 months)., Intervention: FFRs were recorded using the /da/ syllable with and without noise., Data Collection and Analysis: The /da/ syllable and speech-shaped noise were monaurally presented to the participants' right ears through ER-3a insert earphones. Electrodes were placed in M1 and M2 (-), Fz (+), and Fpz (ground). Acquisition occurred under two conditions: (1) the/da/ syllable presented without the noise and (2) the /da/ syllable presented 4 msec after the noise., Results: Data show that (1) considering the mean values of all participants, there was a significant latency delay of all waves (PV, A, PW, PX, PY, PZ, and O) when the /da/ syllable was presented 4 msec after the masking noise as compared with the condition without noise, that is, forward masking occurred in all components of the FFR responses, and (2) for the youngest group and the middle-age group, forward masking was seen for all waves, except PX in the latter one; for the senior group, an irregular pattern was observed (presence of forward masking in PA, PY, PZ, and O). This pattern may be due to an aging effect on FFR responses even without noise presence, which makes it more difficult to identify forward masking effect in this population. Although it is well documented in the literature that forward masking increases with age, this is less evident on FFR recordings in the senior population., Conclusions: An aging effect was identified in FFR responses. Forward masking was identified in FFR responses of all groups but less evident in senior population., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (American Academy of Audiology. All rights reserved.)

Purpose: To evaluate the long-term hearing outcomes in cochlear implanted adults with residual hearing at low frequencies, and the proportion of patients using electro-acoustic stimulation (EAS)., Methods: A monocentric retrospective cohort study was performed in a tertiary referral center. Population demographics, surgical approach, pre- and postoperative hearing at low frequencies, in the implanted and contralateral ear, were recorded as well as duration of EAS use. The percentage hearing preservation was calculated according to the formula S (HEARRING group)., Results: In total, 63 adults (81 ears) with residual hearing underwent cochlear implantation with intent to use EAS processors. Six different types of electrode array were implanted. The mean pure tone audiometry (PTA) shift after cochlear implantation was 16 ± 15 dB HL (range 0-59 dB HL). Half of the implanted ears had minimal hearing preservation or total hearing loss (HL) at 5.5 years and the cumulative risk of total HL was 50% at 7 years. During the follow-up, total HL occurred in 22 ears. The decrease in hearing levels was similar in both implanted and contralateral ear during follow-up (ns, F = 2.46 ± 3, Linear Mixed Model (LMM)). Only 44 patients found a benefit from EAS at the first fitting. At the last visit, EAS processors were fitted in 30% of the cases. The pre- and postoperative mean PTA thresholds were not predictive of EAS use (Cox's proportional hazards analysis)., Conclusions: Postoperative residual hearing was observed in 93% of implanted ears, but only half of them had an initial benefit from EAS. No predictive factors were found to influence the use of EAS processors.

Observer-based procedures are used to assess auditory behavior in infants, often incorporating adaptive tracking algorithms. These procedures are reliable, but effects of modifications made to accommodate infant testing are not fully understood. One modification is that observation intervals are undefined for the listener, introducing signal-temporal uncertainty and increasing the likelihood that listener response bias will influence estimates of performance. The effect of these factors was evaluated by comparing threshold estimates obtained from adults using two tasks: (1) single-interval, yes/no and (2) two-interval, forced-choice. Detection thresholds were estimated adaptively for a 1000-Hz FM tone in quiet and for a word presented in two-talker speech masking. Trials were initiated and judged by the observer (observer-based) or the listener (listener-based). Thus, listening intervals were temporally uncertain in observer-based procedures and temporally defined in listener-based procedures. Thresholds were higher for observer-based relative to corresponding listener-based procedures. The magnitude of this difference was similar across the yes/no and two-interval tasks, and was larger for masked word detection than tone detection in quiet. Listeners adopted a conservative criterion when tested using the observer-based, yes/no procedure, but modeling results suggest that signal-temporal uncertainty accounts for the largest portion of the threshold difference between observer-based and listener-based procedures.

Lip-reading improves intelligibility in noisy acoustical environments. We hypothesized that watching mouth movements benefits speech comprehension in a 'cocktail party' by strengthening the encoding of the neural representations of the visually paired speech stream. In an audiovisual (AV) task, EEG was recorded as participants watched and listened to videos of a speaker uttering a sentence while also hearing a concurrent sentence by a speaker of the opposite gender. A key manipulation was that each audio sentence had a 200-ms segment replaced by white noise. To assess comprehension, subjects were tasked with transcribing the AV-attended sentence on randomly selected trials. In the auditory-only trials, subjects listened to the same sentences and completed the same task while watching a static picture of a speaker of either gender. Subjects directed their listening to the voice of the gender of the speaker in the video. We found that the N1 auditory-evoked potential (AEP) time-locked to white noise onsets was significantly more inhibited for the AV-attended sentences than for those of the auditorily-attended (A-attended) and AV-unattended sentences. N1 inhibition to noise onsets has been shown to index restoration of phonemic representations of degraded speech. These results underscore that attention and congruency in the AV setting help streamline the complex auditory scene, partly by reinforcing the neural representations of the visually attended stream, heightening the perception of continuity and comprehension.

Background: Cochlear implant (CI) listeners had some hearing problems, including catching clues from speech context, persist, particularly in complex listening environments. Among these hearing problems, temporal resolution is considered to be one of the most affected aspects of hearing., Purpose: The aim of the study is to assess and compare the temporal resolution ability of CI users and individuals with normal hearing using the Gaps-in-Noise (GIN) test. This study also aims to investigate whether there are any differences in speech recognition and temporal resolution performance between groups separated according to the implanted ear, gender, CI type, or sound processor strategies., Research Design: Case-control study., Study Samples: 18 adults (9 males, 9 females) with normal hearing, ranging in age between 18 and 55 years (mean: 30.64 ± 8.59 years) and 18 postlingual adults (10 males, 8 females) with bilateral CIs ranging in age between 19 and 59 years (mean: 36.64 ± 16.59 years) were included in the current study., Data Collection and Analysis: Hearing thresholds, word recognition scores (WRS), and GIN test were conducted for each participant. Two parameters of GIN test were determined: the GIN threshold and total percentage score (TPS). Mann-Whitney U test was used to test the significance of the differences between the groups in terms of GIN threshold, WRS, and TPS., Results: CI group showed significantly (p < 0.001) poorer performance in terms of WRS than normal hearing group. However there were no significant differences in WRS between groups which were divided according to the implanted ear, gender, CI type, and sound processor strategies. The mean GIN threshold was 3.33 ± 1.2 msec, whereas it was 9.56 ± 3.49 msec in CI users. Moreover the mean value of TPS was 90.77% in the normal group and 47.22% in the CI group. These differences between the two groups were also found statistically significant (p < 0.001)., Conclusions: Our results show that CI users do not discriminate GIN as well as normal-hearing individuals, although their hearing levels with CIs are very close to normal hearing limits at all frequencies., (American Academy of Audiology.)

Objective: The aim of this study was to determine whether the auditory skills presented by five-year-old children can predict their performance in auditory processing (AP) tests at seven years old., Design: Thirty-five children were evaluated for AP at two different times. At evaluation 1, the children were between 5 years 2 months and 6 years 1 month of age, and at evaluation 2, they were between 7 years 1 month and 7 years 8 months of age. The interval between the evaluations ranged from 18 to 23 months. After evaluation 2, the 7-year-olds were classified according to their performance on central AP tests. The children were divided into three groups: GI included nine children with at least two AP tests that scored two standard deviations below the mean and the presence of a speech complaint; GII included 18 children with at least two AP tests that scored two standard deviations below the mean and no speech complaints; and GIII included eight children with no more than one test scored two standard deviations below the mean and no speech disorders complaint. The analysis was performed considering each test individually and as a battery of applied tests. From the results obtained, a discriminant analysis was performed to assess the differences in test performance between the groups when the children were 5 years old., Results: The discriminant analysis showed that with the results obtained during evaluation 1, it was possible to predict which group 74.3% of the children would be classified into after evaluation 2. The percentage of correct classifications for each group was 77.8% for GI, 66.7% for GII and 87.5% for GIII. That is, 87.5% of the children who were classified as GIII after evaluation 2 had already demonstrated good auditory performance in the tests applied at 5 years of age., Conclusions: Children who exhibited lower scores on AP tests at 7 years of age had demonstrated poor auditory perception at 5 years of age. This finding is relevant because it offers the possibility of stimulating or training these auditory skills in preschoolers to foster their development., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Research has shown that hearing aid acceptance is closely related to how well an individual tolerates background noise, regardless of improved speech understanding in background noise. The acceptable noise level (ANL) test was developed to quantify background noise acceptance. The ANL test measures a listener's willingness to listen to speech in noise rather than their ability to understand speech in noise, and is clinically valuable as a predictor of hearing aid success., Purpose: Noise acceptance is thought to be mediated by central regions of the nervous system, but the underlying mechanism of noise acceptance is not well understood. Higher order central efferent mechanisms may be weaker and/or central afferent mechanisms are more active in listeners with large versus small ANLs. Noise acceptance, therefore, may not be limited to the auditory modality but observable across modalities. We designed a visual-ANL test, as a parallel of the auditory-ANL test, to examine the relations between auditory and visual noise acceptance., Research Design: A correlational design., Study Sample: Thirty-seven adults between the ages of 21 and 30 years with normal hearing participated in this study., Data Collection and Analysis: All participants completed the standard auditory-ANL task, the visual-ANL task developed for this study, reception thresholds for sentences using the hearing in noise test, and visual sentence recognition in noise using the text reception threshold test. Correlational analyses were performed to evaluate the relations between and among the ANL and perception tasks., Results: Auditory- and Visual-ANLs were correlated; those who accepted more auditory noise were also those who accepted more visual noise. Auditory and visual perceptual measures were also correlated, demonstrating that both measures reflect common processes underlying the ability to recognize speech in noise. Finally, as expected, noise acceptance levels were unrelated to perception in noise across modalities., Conclusions: The results of this study support our hypothesis that noise acceptance may not be unique to the auditory modality, specifically, that the common variance shared between the two ANL tasks, may reflect a shared general perceptual or cognitive mechanism that is not specific to the auditory or visual domains. These findings also support that noise acceptance and speech recognition reflect different aspects of auditory and visual perception. Future work will relate these ANL measures with central tasks of inhibition and include hearing-impaired individuals to explore the mechanisms underlying noise acceptance., (American Academy of Audiology.)

Visual information from the face of an interlocutor complements auditory information from their voice, enhancing intelligibility. However, there are large individual differences in the ability to comprehend noisy audiovisual speech. Another axis of individual variability is the extent to which humans fixate the mouth or the eyes of a viewed face. We speculated that across a lifetime of face viewing, individuals who prefer to fixate the mouth of a viewed face might accumulate stronger associations between visual and auditory speech, resulting in improved comprehension of noisy audiovisual speech. To test this idea, we assessed interindividual variability in two tasks. Participants (n = 102) varied greatly in their ability to understand noisy audiovisual sentences (accuracy from 2-58%) and in the time they spent fixating the mouth of a talker enunciating clear audiovisual syllables (3-98% of total time). These two variables were positively correlated: a 10% increase in time spent fixating the mouth equated to a 5.6% increase in multisensory gain. This finding demonstrates an unexpected link, mediated by histories of visual exposure, between two fundamental human abilities: processing faces and understanding speech.

Purpose Listening-related fatigue is an understudied construct that may contribute to the auditory, educational, and psychosocial problems experienced by children with unilateral hearing loss (UHL). Herein, we present an overview of listening-related fatigue in school-age children with hearing loss (CHL), with a focus on children with UHL. Method Following a review of research examining listening-related fatigue in adults and CHL, we present preliminary findings exploring the effects of unilateral and bilateral hearing loss on listening-related fatigue in children. For these exploratory analyses, we used data collected from our ongoing work developing and validating a tool, the Vanderbilt Fatigue Scale, for measuring listening-related fatigue in children. Presently, we are assessing 3 versions of the fatigue scale-child self-report, parent proxy, and teacher proxy. Using these scales, data have been collected from more than 900 participants. Data from children with unilateral and bilateral hearing loss and for children with no hearing loss are compared with adult Vanderbilt Fatigue Scale data. Results Results of our literature review and exploratory analyses suggest that adults and CHL are at increased risk for listening-related fatigue. Importantly, this increased risk was similar in magnitude regardless of whether the loss was unilateral or bilateral. Subjective ratings, based on child self-report and parent proxy report, were consistent, suggesting that children with unilateral and bilateral hearing loss experienced greater listening-related fatigue than children with no hearing loss. In contrast, results based on teacher proxy report were not sensitive to the effects of hearing loss. Conclusions Children with UHL are at increased risk for listening-related fatigue, and the magnitude of fatigue is similar to that experienced by children with bilateral hearing loss. Problems of listening-related fatigue in school-age CHL may be better identified by CHL themselves and their parents than by teachers and specialists working with the children.

One can consider human language to be the Swiss army knife of the vast domain of animal communication. There is now growing evidence suggesting that this technology may have emerged from already operational material instead of being a sudden innovation. Sharing ideas and thoughts with conspecifics via language constitutes an amazing ability, but what value would it hold if our conspecifics were not first detected and recognized? Conspecific voice (CV) perception is fundamental to communication and widely shared across the animal kingdom. Two questions that arise then are: is this apparently shared ability reflected in common cerebral substrate? And, how has this substrate evolved? The paper addresses these questions by examining studies on the cerebral basis of CV perception in humans' closest relatives, non-human primates. Neuroimaging studies, in particular, suggest the existence of a 'voice patch system', a network of interconnected cortical areas that can provide a common template for the cerebral processing of CV in primates. This article is part of the theme issue 'What can animal communication teach us about human language?'

Objectives: The aim of this longitudinal follow-up study was to explore the trajectories of early auditory and language development in Mandarin speaking children younger than 3 years of age following switch-on of their cochlear implants (CIs)., Methods: Early auditory and language development was measured longitudinally using the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS), which is a commonly used tool for assessing early prelingual auditory development (EPLAD) in children, and the subtest (Words and Gestures, W&G) of the simplified short form version of the Mandarin Communicative Development Inventory (SSF-MCDI) to assess receptive and expressive vocabulary growths of children in 24 pediatric cochlea implant recipients at baseline, 3, 6, and 12 months following switch-on. Age at switch-on ranged from 1 to 3 years of age. Participants were divided into two groups based on age at switch-on. The IT-MAIS and SSF-MCDI (W&G) scores were analyzed with comparison to normal children, unaided hearing-impaired children, and CI children., Results: Significant improvements in IT-MAIS and SSF-MCDI (W&G) scores from baseline to 12 months were seen after switch-on in both CI groups and were comparable to the normal hearing children in the first year of age. The IT-MAIS scores of CI children in both groups at 12 months after switch-on surpassed the average level of unaided peers with profound hearing loss and were similar to the average level of unaided peers with mild hearing loss. SSF-MCDI (W&G) scores in word comprehension and expression were significantly different between groups at some intervals., Conclusions: Children younger than 3 years of age with cochlear implants have similar trajectories in early auditory and language developments to normally hearing children. Moreover, early implantation is an important factor for the early auditory development when comparing EPLAD results between CI children and unaided peers with different hearing loss. Finally, it is noteworthy that CI children master the skill of word comprehension before the skill of word expression, and that word comprehension may be the basis of word expression., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In a multi-speaker scenario, a hearing aid lacks information on which speaker the user intends to attend, and therefore it often mistakenly treats the latter as noise while enhancing an interfering speaker. Recently, it has been shown that it is possible to decode the attended speaker from the brain activity, e.g., recorded by electroencephalography sensors. While numerous of these auditory attention decoding (AAD) algorithms appeared in the literature, their performance is generally evaluated in a non-uniform manner. Furthermore, AAD algorithms typically introduce a trade-off between the AAD accuracy and the time needed to make an AAD decision, which hampers an objective benchmarking as it remains unclear which point in each algorithm's trade-off space is the optimal one in a context of neuro-steered gain control. To this end, we present an interpretable performance metric to evaluate AAD algorithms, based on an adaptive gain control system, steered by AAD decisions. Such a system can be modeled as a Markov chain, from which the minimal expected switch duration (MESD) can be calculated and interpreted as the expected time required to switch the operation of the hearing aid after an attention switch of the user, thereby resolving the trade-off between AAD accuracy and decision time. Furthermore, we show that the MESD calculation provides an automatic and theoretically founded procedure to optimize the number of gain levels and decision time in an AAD-based adaptive gain control system.

Objective: Research has found that otitis media (OM) is highly prevalent in Australian Indigenous children, and repeated bouts of OM is often associated with minimal-to-moderate hearing loss. However, what is not yet clear is the extent to which OM with hearing loss impacts auditory signal processing specifically, but also binaural listening, listening in noise, and the potential impact on phonological awareness (PA) - an important, emergent literacy skill. The goal of this study was to determine whether auditory abilities, especially binaural processing, were associated with PA in children from populations with a high incidence of OM, living in a remote Australian Indigenous community in the Northern Territory (NT)., Methods: Forty-seven 5-12-year-olds from a bilingual school participated in the study. All were tested to determine hearing sensitivity (pure tone audiometry and tympanometry), with PA measured on a test specifically developed in the first language of the children. OM often results in a hearing loss that can affect binaural processing: the Dichotic Digit difference Test (DDdT) was used to evaluate the children's dichotic listening and the Listening in Spatialized Noise-sentences test (LiSN-S) was used to evaluate their abilities to listen to speech-in-noise., Results: Seventeen (36%) and 16 (34%) had compromised middle ear compliance (combined Type-B and -C) in the right and left ear respectively. Six children demonstrated a bilateral mild hearing loss, and another five children demonstrated a unilateral mild hearing loss. Thirty-one children were able to complete the DDdT listening task, whereas only 24 completed the speech in noise task (LiSN-S). Forty-four children (94%) were able to complete the letter identification subtask, comprising part of the PA task. The findings revealed that age was significantly correlated with all tasks such that the older children performed better across the board. Once hearing thresholds were controlled for, PA also correlated significantly with both binaural processing tasks of dichotic listening (r = 0.59, p < 0.001) and listening to speech in noise (r = -0.56, p = 0.005); indicating a potential association between early, emergent literacy and listening skills., Conclusions: The significant correlations between phonological awareness and dichotic listening as well as phonological awareness with listening to speech-in-noise skills suggests auditory processing, rather than hearing thresholds per se, are associated to phonological awareness abilities of this cohort of children. This suggests that the ability to process the auditory signal is critical., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

Introduction: The cochlear implant is an effective device for children with severe and/or profound prelingual hearing loss, since it provides considerable improvement in oral language acquisition through the auditory pathway. The use of a cochlear implant contributes to the development of auditory perception, favoring the acquisition of the linguistic processes related to communication skills, which might have a positive effect on other areas of development., Objective: The aim of this study was to verify the performance of children using cochlear implants for expressive and receptive oral language., Methods: This was a prospective cross-sectional study that used the following tests: Child language test in the phonology, vocabulary, fluency and pragmatics areas, and the Peabody picture vocabulary test. Thirty children participated in this study, of both genders, aged between 36 and 72 months, with severe and/or profound bilateral sensorineural hearing loss, without other impairments and users of unilateral cochlear implant with full electrode insertion for a minimum of 12 months., Results: The longer duration of the cochlear implant use, the younger age at surgery and the better performance in the auditory perception of speech influenced the performance in expressive and receptive oral language. Even though when compared to the normative language acquisition process, the results showed that these children had patterns of linguistic skills that are below their chronological age; the results indicate that these children are developing expressive and receptive oral language skills, and this is the outcome that should be taken into account in this study., Conclusion: The longer duration of the cochlear implant use, the younger age at surgery and the better performance in the auditory perception of speech influenced the performance in expressive and receptive oral language skills, but not in all the studied semantic categories., (Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.)