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• Amplitude and synchrony of 40-Hz ASSR was decreased by sound pressure change. • Decrease of amplitude and synchrony depended on magnitude of sound pressure change. • Transient 40-Hz ASSR desynchronization might be an index of change detection. A periodic sound with a fixed inter-stimulus interval elicits an auditory steady-state response (ASSR). An abrupt change in a continuous sound is known to affect the brain's ongoing neural oscillatory activity, but the underlying mechanism has not been fully clarified. We investigated whether and how an abrupt change in sound intensity affects the ASSR. The control stimulus was a train of 1-ms clicks with a sound pressure level (SPL) of 70 dB at 40 Hz for 1000 ms. In addition to the control stimulus, we applied six stimuli with changes consisting of a 500-ms train at 70 dB followed by a 500-ms similar train with louder clicks of 75, 80, or 85 dB or weaker clicks of 55, 60, or 65 dB. We obtained the magnetoencephalographic responses from 15 healthy subjects while presenting the seven stimuli randomly. The two-dipole model obtained for the 40-Hz ASSR in the control condition was applied to all of the stimulus conditions for each subject, and then the time–frequency analysis was conducted. We observed that both the amplitude and the inter-trial phase coherence of the 40-Hz ASSR transiently decreased and returned to the steady state after the change onset, i.e., the desynchronization of 40-Hz ASSR. The degree of desynchronization depended on the magnitude of the change regardless of whether the sound intensity increased or decreased, which might be a novel neurophysiological index of cerebral response driven by a change in the sensory environment. [ABSTRACT FROM AUTHOR]

Background: Cochlear synaptopathy is a disorder where auditory perceptual impairments, such as speech perception in noise and tinnitus, may not be accurately reflected by audiometric thresholds, even if the audiogram appears normal. It is proposed that the connections between hair cells and the auditory nerve are more susceptible to sound and aging damage than the cochlea's hair cells. Cochlear synaptopathy can be present in ears with normal audiograms and undamaged hair cells, leading to hidden hearing loss. This study aims to construct electrophysiological and behavioral auditory parameters associated with persons exposed to loudness and having normal audiograms and auditory complaints to identify hidden hearing loss. Results: A case–control study was done with forty participants with a documented history of exposure to loud sounds and various auditory complaints, compared to a control group of forty persons who had all been confirmed to have normal audiograms. The chosen behavioral core tests comprised the speech intelligibility in noise test (SPIN), gaps detection in noise (GIN test), and pitch pattern sequence test (PPS). The electrophysiological measures utilized in the study were the auditory brainstem response test (ABR) and electrocochleography (ECochG). The SPIN, PPS, and GIN test results demonstrated statistically significant disparities between the control and case groups. The amplitude ratio of wave I to wave V in ABR and the ratio of EcochG AP to SP demonstrated a statistically significant variance between the two groups. The SPIN test exhibited the highest AUC, signifying its superior diagnostic capability in identifying hidden hearing loss. Conclusion: The present study has shown that the SPIN, as a behavioral test, and the EcochG AP amplitude measure, as an electrophysiological test, provide the greatest auditory diagnostic capability for identifying cochlear synaptopathy. Wave I amplitude in the auditory brainstem response (ABR) and the SP/AP ratio in electrocochleography (EcochG) are promising non-behavioral measures of cochlear synaptopathy or hidden hearing loss. [ABSTRACT FROM AUTHOR]

Objective Congenital cytomegalovirus (CMV) infection is a common intrauterine infection and the leading cause of nonhereditary sensorineural hearing loss. This study aims to assess the long-term outcome of the infection and to identify infants at risk of developing long-term sequelae. Methods This retrospective single-center observational study includes infants born between 2003 and 2019 with confirmed congenital CMV (based on current criteria). Brain imaging (ultrasound and magnetic resonance imaging [MRI]), clinical monitoring of neurosensory development, and auditory brainstem evoked responses were performed, as well as long-term neurodevelopmental follow-up to assess sequelae. Results A total of 66 infants with congenital CMV were included in the study. Median gestational age at birth was 38.6 weeks (interquartile range: 36.9–40.1). Clinical findings included intrauterine growth restriction (39%), microcephaly (29%), thrombocytopenia (17%), and jaundice (11%). Brain abnormalities were observed on ultrasound (30%) and MRI (42%). Neurodevelopmental scores were abnormal in 21 subjects (43%) and associate with the vacuolization of anterior temporal lobe and ventricular septations on MRI (both p = 0.05). Fourteen patients (21%) had sensorineural hearing loss, which was more common in patients with abnormal cerebral images at birth, determined by ultrasound (p = 0.06). Microcephaly (p = 0.05) and abnormal MRI (p = 0.03) at birth were associated with poor long-term outcomes. Conclusion Early detection of congenital CMV infection is important to prevent long-term complications in affected infants. Understanding the predictors of poor outcomes may help improving management and treatment strategies for this condition. [ABSTRACT FROM AUTHOR]

BACKGROUND: Varied noise environments, such as impulse noise and steady-state noise, may induce distinct patterns of hearing impairment among personnel exposed to prolonged noise. However, comparative studies on these effects remain limited. OBJECTIVE: This study aims to delineate the different characteristics of hearing loss in workers exposed to steady-state noise and impulse noise. METHODS: As of December 2020, 96 workers exposed to steady-state noise and 177 workers exposed to impulse noise were assessed. Hearing loss across various frequencies was measured using pure tone audiometry and distortion product otoacoustic emission (DPOAE) audiometry. RESULTS: Both groups of workers exposed to steady-state noise and impulse noise exhibited high frequencies hearing loss. The steady-state noise group displayed significantly greater hearing loss at lower frequencies in the early stages, spanning 1– 5 years of work (P < 0.05). Among individuals exposed to impulse noise for extended periods (over 10 years), the observed hearing loss surpassed that of the steady-state noise group, displaying a statistically significant difference (P < 0.05). CONCLUSION: Hearing loss resulting from both steady-state noise and impulse noise predominantly occurs at high frequencies. Early exposure to steady-state noise induces more pronounced hearing loss at speech frequencies compared to impulse noise. [ABSTRACT FROM AUTHOR]

Background: This study utilized recent advancements in electroencephalography (EEG) technology that enable the measurement of prefrontal event-related potentials (ERPs) to facilitate the early detection of mild cognitive impairment (MCI). We investigated two-channel prefrontal ERP signals obtained from a large cohort of elderly participants and compare among cognitively normal (CN), subjective cognitive decline (SCD), amnestic MCI (aMCI), and nonamnestic MCI (naMCI) groups. Methods: Signal processing and ERP component analyses, specifically adapted for two-channel prefrontal ERP signals evoked by the auditory oddball task, were performed on a total of 1,754 elderly participants. Connectivity analyses were conducted to assess brain synchronization, especially in the beta band involving the phase locking value (PLV) and coherence (COH). Time-frequency, time-trial, grand average, and further statistical analyses of the standard and target epochs were also conducted to explore differences among the cognition groups. Results: The MCI group’s response to target stimuli was characterized by greater response time variability (p < 0.001) and greater variability in the P300 latency (p < 0.05), leading to less consistent responses than those of the healthy control (HC) group (CN+SCD subgroups). In the connectivity analyses of PLV and COH waveforms, significant differences were observed, indicating a loss of synchronization in the beta band in response to standard stimuli in the MCI group. In addition, the absence of event-related desynchronization (ERD) indicated that information processing related to readiness and task performance in the beta band was not efficient in the MCI group. Furthermore, the observed decline in the P200 amplitude as the standard trials progressed suggests the impaired attention and inhibitory processes in the MCI group compared to the HC group. The aMCI subgroup showed high variability in COH values, while the naMCI subgroup showed impairments in their overall behavioral performance. Conclusion: These findings highlight the variability and connectivity measures can be used as markers of early cognitive decline; such measures can be assessed with simple and fast two-channel prefrontal ERP signals evoked by both standard and target stimuli. Our study provides deeper insight of cognitive impairment and the potential use of the prefrontal ERP connectivity measures to assess early cognitive decline. [ABSTRACT FROM AUTHOR]

Background: Dizziness in elderly patients is classified as a multifactorial geriatric syndrome leading to pathological conditions or changes endemic to the aging process, it is characterized by increased susceptibility to accidents and instability. This is considered a major public health problem. In our study, we assessed age related changes in vestibular function via measurement of combined Vestibular-Evoked Myogenic potentials (VEMPs) as well as Static Subjective Visual Vertical Test (SVVT) for otolith function. Methods: Seventy-five subjects (150 ears) were enrolled in this research. They were categorized into a control group composed of twenty-five adults from 18–40 years and a study group which divided into symptomatic and asymptomatic groups, each group consisted of twenty-five subjects, fifteen subjects aged 55- < 65 years & ten subjects aged 65 to 85 years. All subjects were submitted to combined VEMPs and static SVVT. Results: Detectability of combined VEMPs decreased with age with significant difference among the older age group (> 65- < 85 years) and the subjects aged (55- < 65 years). Percentage of abnormal cVEMPs & oVEMPs latencies and amplitudes was more detected in the older age group than subjects aged (55- < 65 years). The symptomatic group aged > 65 years showed higher percentage of affection of both cVEMPs & oVEMPs, while the younger group aged 55- < 65 showed higher absence of bilateral oVEMPs. There were no statistically significant differences in the asymmetrical ratio of cVEMPs & oVEMPs between elderly and adults. Static SVV perception does not change with age. Conclusions: The elderly showed variable degrees of otolith dysfunction with a high percentage of affection in cVEMPs and oVEMPs. Also, they showed symptoms of imbalance and light-headedness. Static SVVT perception doesn't change with age. [ABSTRACT FROM AUTHOR]

Simple Summary: The Golden Rabbitfish's consumption of seaweed can seriously harm seaweed beds. To address the issue of their grazing on seaweed beds, sound can be used to deter them. The behavioral reaction of the Golden Rabbitfish to sine wave pulses was examined in this study. According to the findings, the fish responded to low-frequency sine pulses the most, exhibiting a clear escape response. These results allow for future attempts to employ sound to deter Golden Rabbitfish and present a theoretical strategy and data base. This study investigates the auditory capabilities of Golden Rabbitfish (Siganus guttatus) and the potential efficacy of sound-based deterrent methods for behavior control. Behavioral experiments were conducted on Golden Rabbitfish to assess their responses to sound stimuli. Sinusoidal pulses in the range of 100~800 Hz, based on previous research on auditory evoked potentials (AEPs), were utilized. An analysis of behavioral trajectories, swimming speed, and acceleration changes revealed the fish's reactions to varying frequency sound stimuli. The results indicate that Golden Rabbitfish exhibited increased swimming activity and speed when stimulated by sound and notably moved away from the source under prolonged exposure to low-frequency acoustic signals. Specifically, the fish displayed the most significant response to 200 Hz sinusoidal pulses with a response threshold of 113~126 dB. These findings suggest that Golden Rabbitfish are particularly sensitive to low-frequency noise, aligning with AEP study outcomes. This study concludes that employing sound stimuli to deter Golden Rabbitfish in practical settings holds promise for mitigating economic losses in seaweed farming due to Golden Rabbitfish grazing. [ABSTRACT FROM AUTHOR]

Purpose: Many older dogs (Canis lupus familiaris) develop cognitive impairment. Dog owners often describe impairments in multiple sensory functions, yet the relationships between sensory and cognitive function in older dogs is not well understood. Methods: We performed assessments of dog vision and hearing, both clinically (n = 91, electroretinography and brainstem auditory evoked potential) and via validated questionnaire (n = 238). We determined prevalence of sole and dual hearing/vision impairments in younger (<8 years) and older (≥8 years) dogs. Impairment cutoffs were determined using data from young dogs. We assessed the relationships between questionnaire-assessed vision and/or hearing impairments and cognitive impairment using logistic regression. Results: Younger and older dog groups had similar distributions of sex and purebred/mixed breed status. Sex had no relationship to prevalence of sensory impairments. Older dogs had higher prevalence of hearing, vision, and dual sensory impairments, assessed both clinically and by questionnaire (P<0.001), and cognitive impairment assessed by questionnaire (P<0.001). Dogs had higher prevalence of reported cognitive impairment when owners reported dual vision and hearing impairments (79–94%, versus 25–27% in dogs with no sensory impairments), which was most consistent in dogs aged ≥8 years. In these older dogs, dual vision/hearing impairments were associated with a significantly increased risk of cognitive impairment (1.8–2.0 odds ratio). Conclusion: Dogs aged ≥8 years are at higher risk for dual hearing/vision impairments and associated cognitive impairments. The causal relationship between these impairments is not defined, but clinical consideration of these multimorbidity risks should be made in older dogs. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to explore the effect of plateau duration in eliciting masseter vestibular evoked myogenic potentials (mVEMPs) in healthy individuals with hearing sensitivity ≤ 15dBHL. Method: A within-subjects design was utilized in the study. Therefore, ipsilateral tone burst evoked mVEMPs were obtained from 30 healthy individuals using the zygomatic montage at 500 Hz tone bursts. Self-monitoring biofeedback was given during the procedure to confirm the tension of the masseter muscle. mVEMPs were recorded across three different plateau duration from 0 to 2 ms with rise/fall time of 2 ms at 95dBnHL. Hence the median and interquartile range were calculated for descriptive analysis of the data followed by non-parametric inferential statistics. Results: Tone burst evoked mVEMPs were found to be 100% present across all three plateau durations for both ears at 95 dBnHL. P11 and N21 latencies increased with longer plateau durations in both ears. There were no significant differences in P11-N21 peak-to-peak amplitude or interaural amplitude ratio (IAAR) observed across different plateau durations. IAAR was lowest for a 2 ms plateau duration in the 2–2-2 cycle. No significant variations were found across the three plateau durations. Conclusion: Significant differences in P11 and N21 latencies were observed across the three stimulus cycles, while no significant differences were found for P11N21 amplitude and IAAR. Yet, there was found to have the highest amplitude and lowest IAAR for 2–2-2 cycle than 2–0-2 and 2–1-2, suggesting it to be the optimal stimulus among the three of them. [ABSTRACT FROM AUTHOR]

Electrophysiological research has been widely utilized to study brain responses to acoustic stimuli. The frequency-following response (FFR), a non-invasive reflection of how the brain encodes acoustic stimuli, is a particularly propitious electrophysiologic measure. While the FFR has been studied extensively, there are limitations in obtaining and analyzing FFR recordings that recent machine learning algorithms may address. In this study, we aimed to investigate whether FFRs can be enhanced using an "improved" source-separation machine learning algorithm. For this study, we recruited 28 native speakers of American English with normal hearing. We obtained two separate FFRs from each participant while they listened to two stimulus tokens /i/ and /da/. Electroencephalographic signals were pre-processed and analyzed using a source-separation non-negative matrix factorization (SSNMF) machine learning algorithm. The algorithm was trained using individual, grand-averaged, or stimulus token spectrograms as a reference. A repeated measures analysis of variance revealed that FFRs were significantly enhanced (p <.001) when the "improved" SSNMF algorithm was trained using both individual and grand-averaged spectrograms, but not when utilizing the stimulus token spectrogram. Similar results were observed when extracting FFRs elicited by using either stimulus token, /i/ or /da/. This demonstration shows how the SSNMF machine learning algorithm, using individual and grand-averaged spectrograms as references in training the algorithm, significantly enhanced FFRs. This improvement has important implications for the obtainment and analytical processes of FFR, which may lead to advancements in clinical applications of FFR testing. [ABSTRACT FROM AUTHOR]

According to the World Health Organization (WHO), the global tobacco epidemic stands as one of the most significant threats to public health in history. With a staggering death toll exceeding 8 million annually, the impact is profound. Smoking prevalence varies greatly between regions and even within countries of the same region. Currently, the highest rates of male smoking are observed in the Western Pacific nations. In India, tobacco usage, encompassing both smoking and non-smoking forms, remains prevalent. Smoking cigarettes is recognized as a major contributor to various neurological disorders, with oxidative stress implicated as a potential mechanism of smoking-related harm resulting brainstem hypoxia which contributes to abnormalities in brainstem auditory evoked potentials (BAEP), resulting in significant impairment of the functions of the eighth cranial nerve and the brainstem among smokers. This research investigates the profound effects of oxidative stress on brainstem auditory evoked potentials (BAEP), in tobacco smokers. The study encompasses a diverse array of measurements, including anthropometric data, blood pressure, brainstem auditory evoked potentials (BAEP) oxidative stress markers (malondialdehyde - MDA and superoxide dismutase - SOD), and serum electrolytes. The results shed light on the intricate relationship between tobacco smoking, oxidative stress, and neurological outcomes. [ABSTRACT FROM AUTHOR]

Background: Systemic lupus erythematosus (SLE) is a chronic, inflammatory, autoimmune disease, characterized by multiple organ involvement, which is seen more often in young females. Objectives: To evaluate the hearing and balance functions in SLE patients. Materials and methods: Twenty-four SLE patients, 24 healthy controls underwent pure tone audiometry (0.125–16 kHz), VNG, vestibular evoked myogenic potential (VEMP), and video head impulse test (vHIT). Results: A statistically significant difference was determined between the control group and the SLE group at 0.125, 0.25, 0.5, 1.0, 6.0, 8.0, 10, 12, 14, and 16 kHz frequencies. Sensorineural hearing loss was observed in 37.5% of the SLE group. The pursuit test was pathological at the rate of 25% in the SLE group. No response was obtained in six SLE patients in the oVEMP test and four SLE patients in the cVEMP test. The mean posterior SCC VOR gain values were 0.64 ± 0.2 in the SLE group. A significant difference was determined between the groups with respect to posterior SCC VOR gains. Conclusions and significance: Our findings show that SLE disease may negatively affect the hearing system and the vestibular system as well. The current study is the first study to comprehensively evaluate SLE patients with VNG, VEMP, and vHIT tests. [ABSTRACT FROM AUTHOR]

Background: Noise-induced cochlear synaptopathy has recently emerged as a focus in hearing research. Purpose: This study aimed to examine the impact of repeated noise exposure on the quantification and mRNA expression levels of cochlear synapses. Methods: Measurements were conducted at baseline, 1 day, and 14 days post-exposure to 88 or 97 dB SPL noise (2 h/day for 7 days, frequency range 2-20 kHz). Auditory brainstem responses (ABRs), immunofluorescence and quantitative real-time PCR (qRT-PCR) were used to examine the results. Results: 1. Exposure to 88 dB SPL caused minimal changes in ABRs, ribbon morphology and medial olivocochlear (MOC) efferent synapses; elevation of synaptophysin(SYP) and α9α10 nAchR mRNA levels were observed. 2. Exposure to 97 dB SPL caused threshold shift and synaptopathy of ribbon and MOC; downregulation of α10nAchR, SYP and ctbp2 mRNA levels were observed. Conclusion: Noise-induced cochlear synaptic degeneration involves both afferent and efferent synaptopathy. [ABSTRACT FROM AUTHOR]

Offshore windfarms are a key means to produce clean energy as we seek to limit climate change effects. Impulsive pile driving used for their construction in shallow water environments is among the most intense anthropogenic sound sources. There is an increasing understanding that an array of marine invertebrates detects acoustic cues, yet little is known about how pile driving sound could impact their sound detection abilities. We experimentally quantified potential changes in sound sensitivity for an abundant, commercially and ecologically important squid species (Doryteuthis pealeii) exposed to actual in situ pile driving. The pile was 0.3-m diameter and 10-m long; hammer energy reached 16 kJ per strike. Sound detection thresholds were determined using auditory evoked potentials in animals with no exposure, after one 15-min or five repeated 15-min long pile driving sound sequences, corresponding to cumulative sound exposure levels of 110 and 131 dB re (1 μm s−2)2 s for acceleration and 187 and 214 dB re (1 μPa)2 s for pressure. We found no statistical evidence of temporary threshold shifts in any squid exposed to pile driving sound sequences. These results, combined with companion behavioral studies, suggest that squid may be robust to the sound impacts during offshore windfarm construction. [ABSTRACT FROM AUTHOR]

The central auditory system encompasses two primary functions: identification and localization. Spatial release from masking (SRM) highlights speech recognition in competing noise and improves the listening experience when a spatial cue is introduced between noise and target speech. This assessment focuses on the integrity of auditory function and holds clinical significance. However, infants or pre-lingual subjects sometimes provide less reliable results. This study investigates the value of cortical auditory evoked potentials (CAEPs) onset and acoustic change complex (ACC) as an objective measurement of SRM. Thirty normal-hearing young adults (11 males) were recruited. We found the spatial separation of signals and noise (±90° symmetrically) resulted in a signal-to-noise ratio (SNR) improvement of 9.00 ± 1.71 dB behaviorally. It significantly enhanced cortical processing at all SNR levels, shortened CAEP latencies, and increased amplitudes, resulting in a greater number of measurable peaks for ACC. SRM showed mild to moderate correlations with the differences between two conditions in CAEP measures. The regression model combining N1′-P2′ amplitude at 5 dB SNR (R2 = 0.26), P1 amplitude at 0 dB SNR (R2 = 0.14), and P1 latency at −5 dB SNR (R2 = 0.15), explained 45.3% of the variance in SRM. Our study demonstrates that introducing spatial cues can improve speech perception and enhance central auditory processing in normal-hearing young adults. CAEPs may contribute to predictions about SRM and hold potential for practical application. NEW & NOTEWORTHY: The neural encoding of spatial release from masking (SRM) can be observed in normal-hearing young adults. Spatial separation between target and masker improves speech perception in noise and enhances central auditory processing. The behavioral results showed mild-to-moderate correlations with electrophysiological measures, with acoustic change complex (ACC) amplitude being a better indicator than onset components. Cortical auditory evoked potentials (CAEPs) may contribute to predictions about spatial release from masking, especially when behavioral tests are less reliable. [ABSTRACT FROM AUTHOR]

Introduction Cornelia de Lange Syndrome (CdLS) is a genetic disorder in which individuals may present sensorineural and/or conductive hearing loss, and the results of behavioral auditory assessments are not accurate. Objective To characterize the audiological profile of individuals with CdLS through behavioral, electroacoustic, and electrophysiological audiological assessments. Methods The study included 13 individuals of both sexes, aged between 3 and 26 years, with diagnoses confirmed through genetic studies. The following procedures were performed: medical history survey, otoscopy (pure-tone audiometry [PTA], speech audiometry, and acoustic immittance measures), and auditory brainstem response (ABR). Results In total 62.50% of the participants who underwent PTA had abnormal results (all of which were mild), with a predominance of bilateral conductive hearing loss (60%). Regarding tympanometry, 76.93% had abnormal results, most frequently type B (85.72% on the right and 88.89% on the left ear). Acoustic reflexes showed results compatible with tympanometry changes. Changes in ABR latency values compatible with middle-ear impairment were found in 8 of them (66.66%) – 3 had bilateral (37.50%), and 5 had unilateral impairments (62.50%). Conclusion Mild hearing loss was identified in 62.5% of the individuals with CdLS who underwent the behavioral audiological assessment. In the acoustic immittance measures, 76.9% of the participants presented a tympanometry curve characteristic of middle-ear changes. Acoustic reflexes were absent in 84.6% of the subjects. In the ABR, no changes were identified in auditory pathway integrity. On the other hand, changes in the absolute latency values were found, which are characteristic of conductive hearing loss. [ABSTRACT FROM AUTHOR]

Introduction Mismatch negativity (MMN) represents a negative component of event-related potentials, which is mentioned by guidelines as an important tool to provide measurable data regarding the functionality of the auditory system in acoustic processing. However, the literature still lacks reliable data that can support the clinical use of this potential in the complementary diagnosis of central auditory processing (CAP) disorder (CAPD). Objectives To analyze whether MMN assessment might be associated with the CAP behavioral test battery, as well as to assess the effects of auditory ability deficits on MMN responses in the pediatric population. Methods In total, 45 age-matched children participated in the study. They were submitted to the CAP behavior assessment and to MMN. The children were tested with a combination of speech contrast consisting of acoustic syllables [da] versus [ta], governed by the oddball paradigm. Results Mismatch negativity did not show a direct association with a single test but with the combination of the four tests used as a behavioral test battery to identify CAPD. The results also indicated that the auditory ability deficits influenced the measurement of MMN latency (p = 0.003*), but not the amplitude (p = 0.857) or the area (p = 0.577). Conclusion Mismatch negativity was shown to be statistically associated with the battery of tests used to identify deficits in auditory abilities in the studied sample rather than with a single behavioral test. The deficits in auditory abilities were observed in the MMN latency. Mismatch negativity can be used to assess children with CAPD. [ABSTRACT FROM AUTHOR]

Introduction The study of electrophysiological auditory measures with different types of masking makes it possible to understand temporal processing skills and the processes involved in speech recognition in noise situations. The use of modulated masking in cortical measures of hearing enables the obtainment of analysis parameters of the masking release and its impact on neural auditory processing. Objective To investigate the behavior of cortical auditory evoked potentials (CAEPs) with modulated masking in the normal hearing population. Data synthesis A total of 2,159 articles were identified in the initial search; of these, 12 were selected for full reading. After excluding studies that did not meet the eligibility criteria, six articles were included in the present systematic review. The results show that the type of masking has an influence on cortical auditory behavior, indicating a different effect on neural posture rergarding CAEP responses. Modulated noise as masking in the CAEP record generated statistically higher and earlier responses compared with non-modulated/steady noise, evidenced by the results obtained in the meta-analysis with subgroup analysis. These responses may indicate an influence of the type of noise in the neural auditory coding. Conclusion Better responses were observed in modulated masking in terms of the behavior of CAEPs. Decreased latency and increased amplitude of cortical measurements with the use of modulated noise indicate a lower masking effect of this noise in cortical auditory processing, evidencing the masking release phenomenon. [ABSTRACT FROM AUTHOR]

Objective – To study the correlation between P1 latency and the results of clinical language tests (Reynell III and TROG-2), the latter were used as they are recommended for follow-up assessments of children with cochlear implants (Cis) by the Swedish National Quality Register for children with hearing impairment. Design – A clinical cohort study. Study sample – Cross-sectional and consecutive sampling of 49 children with CIs coming for clinical follow-up assessment from March 2017 – December 2019. Results – For all children tested, there was a significant negative correlation (Spearman's rho= −0.403, p = 0.011) between hearing age and P1 latency. A significant correlation between P1 latency and the Reynell III result (Spearman's rho = −0.810, p = 0.015) was found. In the TROG-2 group, there was no significant correlation between their P1 latency and their language test results (Spearman's rho −0.239, p = 0.196). Conclusion – This method seems to be feasible and easily accepted. The study was conducted in a heterogeneous group of children that we meet daily in our clinic. The results indicated that P1 latency has a negative correlation with language development among our youngest patients fitted with CIs and might be a clinical tool to assess the maturation of central auditory pathways. [ABSTRACT FROM AUTHOR]

• Nonlinear maturation of auditory cortex function and structure during infancy and toddlerhood. • Increased myelination in auditory radiations contributes to decreases in auditory evoked response latencies during infancy. • Associations between white-matter structure and speed of auditory response can be observed at the level of individual child. In school-age children, the myelination of the auditory radiation thalamocortical pathway is associated with the latency of auditory evoked responses, with the myelination of thalamocortical axons facilitating the rapid propagation of acoustic information. Little is known regarding this auditory system function-structure association in infants and toddlers. The present study tested the hypothesis that maturation of auditory radiation white-matter microstructure (e.g., fractional anisotropy (FA); measured using diffusion-weighted MRI) is associated with the latency of the infant auditory response (the P2m response, measured using magnetoencephalography, MEG) in a cross-sectional (N = 47, 2 to 24 months, 19 females) as well as longitudinal cohort (N = 18, 2 to 29 months, 8 females) of typically developing infants and toddlers. Of 18 longitudinal infants, 2 infants had data from 3 timepoints and 16 infants had data from 2 timepoints. In the cross-sectional sample, non-linear maturation of P2m latency and auditory radiation diffusion measures were observed. Auditory radiation diffusion accounted for significant variance in P2m latency, even after removing the variance associated with age in both P2m latency and auditory radiation diffusion measures. In the longitudinal sample, latency and FA associations could be observed at the level of a single child. Findings provide strong support for the hypothesis that an increase in thalamocortical neural conduction velocity, due to increased axon diameter and/or myelin maturation, contributes to a decrease in the infant P2m auditory evoked response latency. Infant multimodal brain imaging identifies brain mechanisms contributing to the rapid changes in neural circuit activity during the first two years of life. [ABSTRACT FROM AUTHOR]

[Display omitted] • An increased frequency of the cytosine-cytosine allele in GAD1 rs3749034 polymorphism was found in schizophrenic patients. • A decreased patient oddball task performance was found only in the cohort of cytosine-thymine carriers between study groups. • A higher P300 amplitude and shorter latency in cytosine-cytosine versus cytosine-thymine carriers was observed for both groups. Glutamic acid decarboxylase, an enzyme in GABA biosynthesis, is encoded by the GAD1 gene, the transcriptional activity of which is affected by the rs3749034 polymorphism. The aim was to investigate the effects of rs3749034 on cognitive event-related potentials (P300) in healthy subjects and schizophrenic patients. Determination of rs3749034 polymorphism was performed in 89 healthy volunteers and 109 schizophrenic patients (males). Two-stimulus oddball task performance and P300 auditory evoked potentials were analyzed and patient symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS). An increased frequency of C allele carriers was disclosed in patients. In controls, superior task performance was observed in cytosine - thymine carriers, while a greater P300 amplitude and shorter latency were found in C/C carriers. Analogous effects were found in patients with a disease onset before 25 years of age. Higher N5 and lower P3 and G5 PANSS scales were revealed in C/C homozygotes. The findings substantiate an involvement of GABA-ergic mechanisms in maintaining an optimal excitatory-inhibitory balance and an association of rs3749034 with early-onset disorder and negative symptoms of schizophrenia. These results are important for understanding underlying mechanisms and the development of evidence-based methods for assessing the risk of schizophrenia. [ABSTRACT FROM AUTHOR]

Pelizaeus-Merzbacher-like disease (PMLD, OMIM #608804) is an autosomal recessive hypomyelinating leukodystrophy caused by homozygous variants in the GJC2 gene. It usually presents in the first months of life with nystagmus, developmental delay, and diffuse hypomyelination on brain magnetic resonance imaging (MRI). We report a case of a 3-year-old boy that presented with nystagmus and global developmental delay. MRI showed diffuse hypomyelination, including the cerebellum. Pelizaeus-Merzbacher disease (PMD) was suspected; however, no pathological variants of the PLP1 gene were found. Exome sequencing found variants in the GJC2 gene, leading to a diagnosis of PMLD. The combination of global developmental delay, hypomyelination, and nystagmus in a child should raise suspicion of PMD and PMLD. Unlike PMD, however, hypomyelination of the brainstem and cerebellum are frequently seen and brainstem auditory evoked potentials are usually normal in PMLD. The latter has an overall better prognosis than the former as well. Epidemiological studies on leukodystrophies have found conflicting results on which disease is more common. However, PMLD is a rare leukodystrophy and both PMLD and PMD should be considered in any child with developmental delay, hypomyelination, and nystagmus. [ABSTRACT FROM AUTHOR]

Introduction: Auditory deficiencies have profound implications for the development of communication abilities, social exchange, and cognitive skills. Although advances in technological instrumentation have decreased the age at which it is possible to detect auditory deficits, an absence of electrophysiological or behavioural reaction to sound does not always reflect auditory loss in younger children. Aim of the study: To profile audiological findings of a child with auditory maturation delay associated with Chudley McCullough Syndrome post auditory stimulation. Method: An extensive audiological evaluation, comprising Behavioral Observation Audiometry, Immittance Audiometry, Oto- Acoustic emission, Auditory Brainstem Response, and Cortical Auditory Evoked Potentials, was performed on a 6-month-old infant. After the audiological evaluation, the infant received auditory stimulation for two months. A comparable audiological assessment was conducted after auditory training. Results: The infant was diagnosed to have severe to profound hearing loss in both ears with noticeable cochlear microphonics in ABR on pre stimulation testing. As a result, he was recommended and had undergone auditory stimulation for two months. Audiological testing post auditory stimulation revealed significant improvements in auditory responses and noticeable betterment in auditory thresholds. Conclusion: Detailed audiological test battery is necessary in determining auditory maturation delay. Intensive auditory stimulation should be provided before concluding on the auditory management. [ABSTRACT FROM AUTHOR]

Purpose: The auditory brainstem response (ABR) can be elicited by broadband stimuli such as the click and chirp. Differences in the click- and chirp-evoked ABR have been extensively described using subjective analyses. The aim of the current research is to determine if subjectively observed differences between the click- and chirp-evoked ABR are also represented in objective signal-tonoise ratio (SNR) measurements obtained from these responses at different stimulus intensities and sweep counts. Method: ABRs were collected using click and chirp stimuli on nine adults with normal hearing sensitivity. Three SNR methods (split-sweep average--based SNR [SSA-SNR], F ratio--based single-point [Fsp], and multipoint [Fmp]) were used for the objective analysis of the waveforms at four stimulus intensities (20, 40, 60, and 80 dB nHL) and five sweep counts (100, 200, 300, 400, and 500 sweeps). Results: SSA-SNR measurements were statistically stronger for chirp- as compared to click-evoked ABRs. Additionally, chirp/click SSA-SNR, Fsp, and Fmp ratio measurements were consistently greater than 1. The advantage associated with the chirp was most noticeable at moderate stimulus intensities for all three measurements. Discussion: The advantages for the chirp observed here could have implications for threshold estimation and screening ABR tests. Furthermore, when stimulus intensity and sweep count were varied, general response trends suggest that the three SNR-based methods performed similarly to each other, as well as to traditionally used subjective measures, suggesting that these techniques have the potential to be used effectively in clinic. [ABSTRACT FROM AUTHOR]

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Introduction: Auditory deficiencies have profound implications for the development of communication abilities, social exchange, and cognitive skills. Although advances in technological instrumentation have decreased the age at which it is possible to detect auditory deficits, an absence of electrophysiological or behavioural reaction to sound does not always reflect auditory loss in younger children. Aim of the study: To profile audiological findings of a child with auditory maturation delay associated with Chudley McCullough Syndrome post auditory stimulation. Method: An extensive audiological evaluation, comprising Behavioral Observation Audiometry, Immittance Audiometry, Oto- Acoustic emission, Auditory Brainstem Response, and Cortical Auditory Evoked Potentials, was performed on a 6-month-old infant. After the audiological evaluation, the infant received auditory stimulation for two months. A comparable audiological assessment was conducted after auditory training. Results: The infant was diagnosed to have severe to profound hearing loss in both ears with noticeable cochlear microphonics in ABR on pre stimulation testing. As a result, he was recommended and had undergone auditory stimulation for two months. Audiological testing post auditory stimulation revealed significant improvements in auditory responses and noticeable betterment in auditory thresholds. Conclusion: Detailed audiological test battery is necessary in determining auditory maturation delay. Intensive auditory stimulation should be provided before concluding on the auditory management. [ABSTRACT FROM AUTHOR]

Introduction: Although a broadband acoustic click is physically the shortest duration sound we can hear, its peripheral neural representation is not as short because of cochlear filtering. The traveling wave imposes frequency-dependent delays to the sound waveform so that in response to a click, apical nerve fibers, coding for low frequencies, are excited several milliseconds after basal fibers, coding for high frequencies. Nevertheless, a click sounds like a click and these across-fiber delays are not perceived. This suggests that they may be compensated by the central auditory system, rendering our perception consistent with the external world. This explanation is difficult to evaluate in normal-hearing listeners because the contributions of peripheral and central auditory processing cannot easily be disentangled. Here, we test this hypothesis in cochlear implant listeners for whom cochlear mechanics is bypassed. Method: Eight cochlear implant users ranked in perceived duration 12 electrical chirps of various physical durations and spanning the cochlea in the apex-to-base or base-to-apex direction (Exp. 1). Late-latency cortical potentials were also recorded in response to a subset of these chirps (Exp. 2). Results: We show that an electrical chirp spanning the cochlea from base-to-apex is perceived as shorter than the same chirp spanning the cochlea in the opposite direction despite having the same physical duration. Cortical potentials also provide neural correlates of this asymmetry in perception. Conclusion: These results demonstrate that the central auditory system processes frequency sweeps differently depending on the direction of the frequency change and that this processing difference is not simply the result of peripheral filtering. [ABSTRACT FROM AUTHOR]

Introduction: Aided auditory late latency response (LLR) serves as an objective tool for evaluating auditory cortical maturation following cochlear implantation in children. While aided LLR is commonly measured using sound-field acoustic stimulation, recording electrically evoked LLR (eLLR) offer distinct advantages, such as improved stimulus control and the capability for single electrode stimulation. Hence, the study aimed to compare eLLR responses with single electrode stimulation in the apical, middle, and basal regions and to evaluate their relationship with speech perception in paediatric cochlear implant (CI) recipients. Method: eLLR responses with single electrode stimulation were measured in 27 paediatric unilateral CI users with an active recording electrode placed at Cz. The stimuli consisted of 36 msec biphasic pulse trains presented across three electrode sites (apical-E20, middle-E11, and basal-E03). eLLR responses were compared across these electrode sites, and the relationship between speech recognition scores in quiet and age at implantation with eLLR components was evaluated. Results: eLLR responses were detected in 77 out of 81 tested electrodes of all participants combined (27 for apical, 26 for middle, and 24 for basal stimulation). There were no significant differences in P1, N1 latencies and P1 amplitude across electrode site. However, significantly larger N1 and P1-N1 amplitudes were observed for apical stimulations compared to basal stimulations. No differences in N1 amplitude were found between middle and apical stimulations, and the P1-N1 amplitude was significantly larger for middle compared to basal electrode stimulation, with no difference between the apical and middle electrodes stimulation. A moderate positive correlation was present between speech recognition scores in quiet and both N1, P1-N1 amplitudes for apical stimulation. Age at implantation was negatively correlated with N1 amplitude for the apical and P1-N1 amplitude for basal stimulation. Discussion: eLLR responses could be elicited in majority of paediatric CI users across electrode sites. Variations in eLLR responses across electrode sites suggest disparities in auditory cortical maturation. The findings underscore the significance of the N1 biomarker in evaluating higher-order auditory cortical development. Therefore, utilizing eLLR with single electrode stimulation may serve as a valuable tool for assessing post-cochlear implantation maturational changes in paediatric populations. [ABSTRACT FROM AUTHOR]

Background: The study explored the differences in audiological and non-audiological characteristics between congenital, early-onset, and late-onset auditory neuropathy spectrum disorder (ANSD). Ninety-five individuals diagnosed with ANSD were included in the study. They were divided into three groups congenital ANSD—children (30 individuals, 60 ears), adults with early-onset ANSD (30 individuals, 56 ears), and adults with late-onset ANSD (35 individuals, 62 ears). The non-audiological characteristics (gender, laterality, and risk factors) and audiological characteristics (behavioral and electrophysiological measures) were compared between the three groups. Results: Discriminant analyses showed that the pure tone average, audiogram configuration, and speech thresholds were the best auditory predictors of onset-based group differences in ANSD (congenital and early-onset versus late-onset ANSD). While the congenital and early-onset group showed poorer pure-tone and speech thresholds, along with flat configuration, the late-onset group demonstrated relatively better thresholds and other configurations (rising, tent-shaped, cookie-bite). In addition, long latency responses were delayed or absent in children with congenital ANSD, indicative of onset coding deficits at the cortical level. Conclusions: The study highlights the audiological differences between congenital, early-, and late-onset ANSD groups. These differences could be because of variations in etiology, pathophysiology, site of lesion, or genetic variability between the groups, which needs to be explored further. [ABSTRACT FROM AUTHOR]

Background: Cochlear implants made a great impact in the management of severe-to-profound hearing loss in both children and adults. Its greatest impact is in helping children born with a profound hearing loss and implanted early to attend mainstream education and using spoken language to communicate. However, the final outcome in pediatric implantation is not predictable as there are large number of factors which will affect the outcome of cochlear implantation. Studying these determinants increases the ability of clinicians to offer educated preoperative prognosis and might potentially allow for manipulation of variables in an attempt to achieve the best possible outcome. Objective: The aim of this study was to assess the preoperative factors affecting the audiological, speech, and language outcomes achieved by the recipients of cochlear implants. Methodology: A total of 39 children with severe-to-profound sensory neural hearing loss were implanted with cochlear implants. Children had received their implants before age of 5 years. Tests of receptive, expressive language quotient, aided cortical auditory-evoked potential using speech stimulus, aided free field audiometry, and aided speech reception thresholds were administered. Characteristics of the child and the family (age before implant and duration of implant use, cause of hearing loss, preimplant use of hearing aids and language therapy, and sociodemographic characteristics of their families) were the preoperative variables. These variables were considered predictors of audiological and language outcomes achieved by children and were determined using statistical analysis by univariate and multivariate analyses. Results: Age of the studied children at time of cochlear implantation was statistically significant predictor for CI outcome as regard receptive language quotient and also for N1 latency. Hearing age of the studied children was a statistically significant predictor for CI outcome as regards P1 latency. Conclusion: Based on our findings, two most important factors affecting outcome of cochlear implantation were the age at implantation and the hearing age. Other factors were important but did not affect the outcome significantly. [ABSTRACT FROM AUTHOR]

This document is a summary of a collection of articles on the roles of temporal precision, synchronization, and neural oscillations in brain function. The articles discuss innovative methodologies for analyzing brain oscillations and their importance in understanding neural circuit dynamics and brain functions. They also highlight the relevance of neural oscillations in speech and music processing, as well as in neurodevelopmental disorders like dyslexia and stuttering. The articles offer valuable perspectives for both research and clinical applications. [Extracted from the article]

An adult pet tawny owl (Strix aluco) presented to a veterinary hospital at Parma University with a history of head trauma. After a critical care protocol including thermal, oxygen and fluid support aimed at stabilizing the patient, a neurological examination was performed. During neurological evaluation, marked lethargy and an inability to rise from a recumbent position was noted. Anisocoria was also present, with a mydriatic left pupil exhibiting no pupillary light response (PLR) even on direct illumination of both eyes. On ocular fundus examination, retinal hemorrhage and retinal detachment were observed. Based on these clinical findings, a complete work-up was performed, including hematological exams and total body X-ray studies followed by a computed tomography (CT) scan. Additional examinations, such as brainstem auditory evoked response (BAER) measurement and flash visual evoked potential (FVEP) recording, were performed. FVEP measurements performed on the left eye exhibited no peaks in either series of stimulations, indicating an altered functional integration within the visual pathway. A CT scan revealed a large hypoattenuating lesion within the right cerebral hemisphere, suspected to be intraparenchymal edema. The BAER test demonstrated an altered trace consistent with brainstem involvement and left hypoacusis due to cranial nerve VIII deficiency. Head trauma can result in significant neurological impairments in birds, impacting their behavior, mobility, and cognitive abilities. FVEP recordings, BAER tests and CT scans may be useful diagnostic tools in clinical practice. Understanding the causes and neurologic presentation of avian traumas is essential for effective prevention, diagnosis and treatment of affected birds. [ABSTRACT FROM AUTHOR]

Introduction: Auditory training (AT) exercises as the main part of auditory rehabilitation have emerged as a promising method for enhancing auditory perception and communication skills in individuals with hearing impairments or difficulties in auditory processing. Through AT, the central auditory nervous system (CANS) undergoes changes that optimize neural circuits, resulting in improved auditory perception. Auditory-evoked potentials (AEPs), including the auditory brainstem responses (ABRs) and cortical auditory-evoked potentials (CAEPs), offer objective measurements of neural responses and serve as valuable biomarkers to assess the effectiveness of AT. Methods: For this systematic review, we conducted a comprehensive search in multiple databases, including MEDLINE (via PubMed), Science Direct, Web of Science, and SciELO, up until August 18, 2023. There were no study type restrictions or limitations on publication time. Following a careful assessment of the article quality and their alignment with the inclusion and exclusion criteria, a total of 25 articles were selected for inclusion in this study. Results: Based on the findings of the reviewed studies, it has been reported that AT exercises lead to an increase in the amplitude of waves in both brainstem and cortical AEPs, with the exception of P1 and N2 waves. Furthermore, it has been observed that the latency of these responses decreases following AT. Conclusion: The application of brainstem and cortical AEPs as objective electrophysiological tools holds promise in assessing the effectiveness of AT exercises and confirming the selected approach for AT. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the utility of auditory steady-state responses (ASSRs) to narrow-band chirps (NB-chirps) for estimating hearing levels in children. Design: Thresholds from the NB-chirp ASSR were evaluated in 30 sedated children with normal hearing or hearing loss. The correlation between the NB-chirp ASSR and pure-tone audiometry (PTA) thresholds was analyzed, and the difference score (DS) between these thresholds was calculated. Data from the NB-chirp ASSR were compared to retrospective data from conventional ASSR to exponentially amplitude-modulated tones in 25 sedated children. Results: Positive correlations between the NB-chirp ASSR and PTA thresholds were found at 500, 1,000, 2,000, and 4,000 Hz. Multiple comparisons of the DSs for the NB-chirp ASSR and PTA revealed significant differences at 500–2,000 Hz and 4,000 Hz, as well as 1,000–2,000 Hz, and 4,000 Hz. Comparisons of the DSs demonstrated that the DS of the NB-chirp ASSR was significantly smaller than that of the conventional ASSR at 2,000 Hz. Furthermore, the testing times for the NB-chirp ASSR were significantly shorter than those for the conventional ASSR. Conclusion: The NB-chirp ASSR closely reflected the PTA thresholds, and the testing time was shorter than that of the conventional ASSR. Thus, this study demonstrated that the NB-chirp ASSR is useful for hearing threshold estimation in children. [ABSTRACT FROM AUTHOR]

Background: Usher's syndrome type II (USH2) is a rare genetic disorder encompassing hearing loss, vision impairment, and apparent intact vestibular function. Recent research suggests a potential involvement of the otolith vestibular receptors in USH2. Aims/Objectives: Evaluate otolith dynamic function in USH2. Material and Methods: Twenty-two USH2 (median age 53.9 ± 2.99) and age-matched controls underwent a complete battery vestibular testing including air conducted cervical and ocular vestibular evoked myogenic potentials (c-VEMPs and o-VEMPs). Vestibular function tests were correlated with Activities Balance Scale (ABC) and Dizziness Handicap Inventory (DHI) scores. Results: Fourteen USH2 reported previous vertigo (vs none control). Among 88 ears, c-VEMPs were absent in 15 USH2 cases and 4 controls (p = 0.034), while o-VEMPs were absent in 22 USH2 cases and 12 controls (p = 0.129). There were significant differences between USH2 vs controls in right ear o-VEMP N1 latencies (median 11.60/10.40, p < 0.010), N1-P1 amplitudes (median 5.15/10.10, p < 0.003) and in o-VEMP N1-P1 asymmetry ratio (median 24.78/40.50, p < 0.014). USH2 showed a strong correlation between o-VEMP amplitude and DHI score (p = 0.003, ρ = 0.769). No association was found between vertigo and VEMPs subgroups. Conclusions and Significance: Our findings suggest the presence of otolith dysfunction in USH2, which is independent from subjectively reported dizziness. Incorporating vestibular testing into USH2 evaluation and monitoring could enhance characterization of this multisensory disease. [ABSTRACT FROM AUTHOR]

We studied the function of the auditory system in Wistar rats after repeated intravenous administration of nicotinamide riboside (NR). The functional activity of the receptor and retrocochlear parts of the auditory system were assessed by recording short-latency auditory evoked potentials (SLAEPs) and distortion-product otoacoustic emissions (DPOAEs) at baseline, immediately after NR administration, and 1 and 2 months later. Repeated intravenous NR administration (cumulative dose of 2700 mg/kg) to Wistar rats has a detrimental impact on the structures within the cochlear section of the auditory system. [ABSTRACT FROM AUTHOR]

Auditory steady-state response (ASSR) is the result of the brain's ability to follow and entrain its oscillatory activity to the phase and frequency of periodic auditory stimulation. Gamma-band ASSR has been increasingly investigated with intentions to apply it in neuropsychiatric disorders diagnosis as well as in brain–computer interface technologies. However, it is still debatable whether attention can influence ASSR, as the results of the attention effects of ASSR are equivocal. In our study, we aimed to systemically review all known articles related to the attentional modulation of gamma-band ASSRs. The initial literature search resulted in 1283 papers. After the removal of duplicates and ineligible articles, 49 original studies were included in the final analysis. Most analyzed studies demonstrated ASSR modulation with differing attention levels; however, studies providing mixed or non-significant results were also identified. The high versatility of methodological approaches including the utilized stimulus type and ASSR recording modality, as well as tasks employed to modulate attention, were detected and emphasized as the main causality of result inconsistencies across studies. Also, the impact of training, inter-individual variability, and time of focus was addressed. [ABSTRACT FROM AUTHOR]

This study investigated the dominant blue eyes (DBE) trait linked to hearing impairment and variable white spotting in Maine Coon cats. Fifty-eight animals descending from 2 different DBE lineages, the Dutch and the Topaz lines, were sampled. They comprised 48 cats from the Dutch bloodline, including 9 green-eyed and 31 blue-eyed cats, with some individuals exhibiting signs of deafness, and 8 stillborn kittens. Samples from the Topaz lineage included 10 blue-eyed animals. A brainstem auditory evoked response test revealed a reduced to absent response to auditory stimuli and absent physiological waveforms in all of the 8 examined DBE animals. We sequenced the genome of 2 affected cats from the Dutch line and searched for variants in 19 candidate genes for the human Waardenburg syndrome and pigmentary disorders. This search yielded 9 private protein-changing candidate variants in the genes PAX3 , EDN3 , KIT , OCA2 , SLC24A5 , HERC2 , and TYRP1. The genotype–phenotype cosegregation was observed for the PAX3 variant within all animals from the Dutch lineage. The mutant allele was absent from 461 control genomes and 241 additionally genotyped green-eyed Maine Coons. We considered the PAX3 variant as the most plausible candidate—a heterozygous nonsense single base pair substitution in exon 6 of PAX3 (NC_051841.1:g.205,787,310G>A, XM_019838731.3:c.937C>T, XP_019694290.1:p.Gln313*), predicted to result in a premature stop codon. PAX3 variants cause auditory–pigmentary syndrome in humans, horses, and mice. Together with the comparative data from other species, our findings strongly suggest PAX3 :c.937C>T (OMIA:001688-9685) as the most likely candidate variant for the DBE, deafness, and minimal white spotting in the Maine Coon Dutch line. Finally, we propose the designation of DBERE (Rociri Elvis Dominant Blue Eyes) allele in the domestic cat. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine if there are age-related differences in semantic processing with linguistic and nonlinguistic masking, as measured by the N400. Method: Sixteen young (19-31 years) and 16 middle-aged (41-57 years) adults with relatively normal hearing sensitivity were asked to determine whether word pairs were semantically related or unrelated in three listening conditions: quiet, forward, and reverse two-talker speech competition at 0 dB SNR. Behavioral data (accuracies and reaction times) and auditory event-related potential data (N400 amplitudes and latencies) were analyzed using separate mixed design multivariate analysis of variances. Results: Mean N400 amplitudes for semantically related word pairs were similar between young and middle-aged adults. Although neither group showed N400 amplitude differences between masker types, N400 amplitude was significantly greater in the presence of linguistic and nonlinguistic masking than in quiet. In contrast, mean N400 amplitudes for semantically unrelated words were significantly more negative for young adults and not significantly different among listening conditions. Conclusions: Our findings illustrated age-related differences during a semantic processing task, as indexed by the N400, that may not be evident in suprathreshold speech repetition/recognition tasks or behavioral data. Additionally, N400 amplitudes indicated that linguistic masking effects were equivalent to nonlinguistic masking effects on semantic processing. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the characteristics of auditory processing (AP) in preschool children with attention-deficit/hyperactivity disorder (ADHD) using the speech auditory brainstem response (speech-ABR), which provides insights into the AP of speech signals in the central auditory nervous system (CANS). Method: A total of 84 preschool children diagnosed with ADHD, aged 4-6 years, were matched with 84 typically developing (TD) children based on gender and age. All children underwent speech-ABR testing, cognitive assessment using the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition or the Wechsler Intelligence Scale for Children-Fourth Edition, and a continuous performance test. Results: Children with ADHD exhibited significantly longer latencies of speech-ABR waveforms V, A, and D compared to TD children. Multiple linear regression analysis showed that the latencies of speech-ABR waves V, A, and D were affected by the presence of ADHD, but not by the full-scale intelligence quotient. Conclusions: This study revealed that preschool children with ADHD exhibited abnormal AP of speech signals in their CANS. The findings suggest that speech-ABR can be utilized as a reliable measure to evaluate AP ability in this population, as it remains unaffected by cognitive or attentional factors. The transient response (V, A) of speech-ABR was found to be a significant predictor of ADHD in a clinical setting. Early assessment of AP abnormalities via speech-ABR is recommended in preschool-age children to develop targeted interventions for ADHD. [ABSTRACT FROM AUTHOR]

Purpose: Target word activation in picture naming was explored in children who stutter (CWS) and typically fluent children (TFC) using event-related potentials (ERPs). Method: A total of 18 CWS and 16 TFC completed a task combining picture naming and probe word identification. On each trial, a picture-to-be-named was followed by an auditory probe word-to-be-identified; the probe was identical (Identity condition) or Unrelated to the picture name. ERPs were recorded from probe onset. Attenuation of the N400 ERP component was predicted to Identity versus Unrelated trials (N400 priming). Between-groups differences in amplitude, timing, and topography of N400 priming were explored. Results: Naming was more accurate on Identity versus Unrelated trials. Probe word identification accuracy was not affected by Condition. N400 priming was detected, indicating that self-generated picture names facilitated semantic processing of identical probes. This effect was larger in amplitude in CWS versus TFC. Unexpectedly, an N400-preceding, frontally maximal, positive-going ERP component--associated with expectancy processing--was larger in amplitude to Unrelated versus Identity trials. This effect was smaller in CWS versus TFC. Conclusions: A larger N400 priming effect in CWS versus TFC reflects a tendency toward more extensive semantic processing in picture naming in CWS. A smaller Condition effect on frontally maximal, positive-going, N400-preceding ERP activity in CWS versus TFC indicates a reduced ability to form expectancies about the lexical and/or phonological identity of probe words in CWS. Both effects may point to inefficient activation of target words in picture naming in CWS. [ABSTRACT FROM AUTHOR]

Background: Recent technological evolutions allow for the identification of hearing level (HL) in infants soon after birth. The goal of early hearing detection and intervention is to maximize linguistic and communication skills and literacy development for children who are deaf or hard of hearing. Infants whose HL has been confirmed before 6 months of age must be provided early intervention. Aims and Objectives: The aim of the study was to observe the changes in the otoacoustic emissions (OAE) and brainstem auditory evoked potential (BAEP) in infants with birth asphyxia (BA). Materials and Methods: The present study was a case– control study. A total of 50 cases of infants with BA and 50 normal-term infants were part of the study after obtaining informed consent as per the ICMR guidelines. A through clinical examination and otoscopy examination were done to rule out any conductive hearing loss. Then, OAE and BAEP were recorded to estimate the hearing loss and hearing threshold of infants. Results: BAEP waveform I, III, and V absolute latencies were significantly prolonged among BA infants than normal infants. The interpeak latency (IPL) of the right ear III-V was significantly increased in BA infants. However, III-V and I-V latencies though prolonged in BA infants, they are not statistically significant. No significant interaural difference was noted in absolute and IPLs of both BA and normal infants. No significant relationship existed between the mode of delivery and the degree of hearing loss in both ears. Significant association was observed between the degree of hearing loss and severity of BA (hypoxic-ischemic encephalopathy) in both ears. Conclusion: BAEP recording in BA infants is useful to identify the hearing impairment at the earliest. The implication of this research work will help in early detection of hearing impairment, so that speech and language developmental delay in the child can be prevented. [ABSTRACT FROM AUTHOR]

The matched filter hypothesis proposes a close match between senders and receivers and is supported by several studies on variation in signal properties and sensory-processing mechanisms among species and populations. Importantly, within populations, individual variation in sensory processing may affect how receivers perceive signals. Our main goals were to characterize hearing sensitivity of Pacific treefrogs (Pseudacris regilla), assess patterns of individual variation in hearing sensitivity, and evaluate how among-individual variation in hearing sensitivity and call frequency content affect auditory processing of communication signals. Overall, males and females are most sensitive to frequencies between 2.0 and 2.5 kHz, which matches the dominant frequency of the call, and have a second region of high sensitivity between 400 and 800 Hz that does not match the fundamental frequency of the call. We found high levels of among-individual variation in hearing sensitivity, primarily driven by subject size. Importantly, patterns of among-individual variation in hearing differ between males and females. Cross-correlation analyses reveal that among-individual variation in hearing sensitivity may lead to differences on how receivers, particularly females, perceive male calls. Our results suggest that individual variation in sensory processing may affect signal perception and influence the evolution of sexually selected traits. [ABSTRACT FROM AUTHOR]

Purpose: Magnetic resonance imaging (MRI), electric compound action potential (eCAP), and electric auditory brainstem response (eABR) are among the routine assessments performed before and/or after cochlear implantation. The objective of this review was to systematically summarize and critically appraise existing evidence of the prognostic value of eCAP, eABR, and MRI for predicting post--cochlear implant (CI) speech perception outcomes in children, with a particular focus on the lesion site. Method: The present systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Three electronic databases (ProQuest, PubMed, and Scopus) were searched with no restrictions on language, publication status, or year of publication. Studies on children identified with sensorineural hearing loss, auditory neuropathy spectrum disorder, cochlear nerve deficiency, or cochleovestibular nerve abnormalities reporting the relevance of eCAP, eABR, and/or MRI results to CI speech perception outcomes were included. The literature search yielded 1,887 publications. Methodological quality and strength of evidence were assessed by the Crowe Critical Appraisal Tool and the Grading of Recommendations Assessment, Development, and Evaluation tool, respectively. Results: Of the 25 included studies, the relevance of eCAP, eABR, and/or MRI findings to post-CI speech perception outcomes was reported in 10, 11, and 11 studies, respectively. The studies were strongly in support of the prognostic value of eABR and MRI for CI outcomes. However, the relevance of eCAP findings to speech perception outcomes was uncertain. Conclusion: Despite the promising findings, caution is warranted in interpreting them due to the observational and retrospective design of the included studies, as well as the heterogeneity of the population and the limited control of confounding factors within these studies. Supplemental Material: https://doi.org/10.23641/asha.26169859 [ABSTRACT FROM AUTHOR]

Purpose: The primary objective of this study was to assess how age influences masseter vestibular evoked myogenic potential (mVEMP) parameters by utilizing 500-Hz tone burst stimuli delivered through air conduction. Method: The study involved 110 participants ranging from 15 to 60 years of age, grouped into five categories, all of whom had no previous issues related to their vestibular system. The participants were exposed to 500-Hz tone burst stimuli at 125 dB SPL through ER-3A inserts. These stimuli were presented to one ear at a time, with alternating polarity. A Tukey's honestly significant difference test was conducted to compare rectified and unrectified amplitude, along with latencies (P11 and N21) and the asymmetric ratio across all age groups. Additionally, a multivariate analysis of variance was performed to assess the impact of sex on the study variables. Results: All 110 participants (220 ears) in the study provided mVEMP responses, encompassing 100% of the subjects. The results revealed a significant reduction in both amplitude and latency extension for the P11 and N21 peaks. Interestingly, P11 latency was also prolonged in the youngest participants (Group 1), suggesting ongoing maturation of the system even beyond the age of 16 years. Moreover, a significant sex difference was observed in the P11 latencies. However, there were no substantial sex differences (p >.05)inN1peaklatency,peak-to- peak amplitude, rectified amplitude, and asymmetric ratio. Conclusions: Changes in structure occur due to degeneration, and the quantity of vestibular sensory hair cells gradually diminishes with age. The rate of decline is faster in semicircular canals compared to end organs, as observed by Merchant et al. (2000). Following a linear degeneration starting at the age of 40 years, a continuous reduction in sensory cells and primary neurons takes place until approximately 40% of vestibular sensory cells are lost by the age of 75 years and insufficient maturation can lead to prolonged peaks and reduced amplitudes compared with those that are considered normal. Therefore, it is crucial to consider the age of the participants when making diagnoses and incorporate relevant correction factors based on age-related reference data. [ABSTRACT FROM AUTHOR]

Agrammatic aphasia poses challenges in assessing grammatical abilities due to language comprehension difficulties. The suitability of sMMN as an indicator of syntactic processing abilities in these individuals remains uncertain. Two ERP experiments were conducted to investigate whether early syntactic mismatch negativity (sMMN) could assess the syntactic processing ability of Chinese-speaking individuals with agrammatic aphasia. Prior to the ERP experiments, the Western Aphasia Battery (WAB) and the Northwestern Assessment of Verbs and Sentences-Chinese (NAVS-C) were used to screen people with agrammatism. ERP data were collected for both the agrammatic group (AG) (n = 12) and the control group (CG) (n = 12). The first experiment (Experiment 1) involved a passive tone oddball task to control for the influence of primary sound perception. The second experiment (Experiment 2: experiment 2a and experiment 2b) investigated syntactic processing through a passive speech oddball task. Experiment 2a examined the processing of correct sentences and syntactic violation sentences in context. In contrast, Experiment 2b assessed well-formed sequences and ill-formed sequences out of context. The results revealed that frontocentral distributed acoustic MMNs were recorded for the CG between 176 - 196ms in Experiment 1, but not for the AG. In Experiment 2, during the 143 - 173ms window, the left anterior sMMN was exclusively observed for the CG, while the left posterior sMMN was specific to the AG. Furthermore, the amplitudes of the left posterior sMMN (143-173ms) were found to have a negative correlation with scores on sentence comprehension tests: the more negative the sMMN, the lower the scores of people with agrammatic aphasia. Notably, this left posterior MMN was absent in Experiment 1. The early posterior sMMN, discovered for the first time in our study, appears to be more sensitive in detecting syntactic processing impairments in agrammatics compared to the early anterior sMMN. This finding has the potential to enhance the precision of aphasia assessment. [ABSTRACT FROM AUTHOR]

This study examined the effect of attention on auditory processing in autistic individuals. Electroencephalography data were recorded during two attention conditions (passive and active) from 24 autistic adults and 24 neurotypical controls, ages 17–30 years. The passive condition involved only listening to the clicks and the active condition involved a button press following single clicks in a modified paired-click paradigm. Participants completed the Adolescent/Adult Sensory Profile and the Social Responsiveness Scale 2. The autistic group showed delayed N1 latencies and reduced evoked and phase-locked gamma power compared to neurotypical peers across both clicks and conditions. Longer N1 latencies and reduced gamma synchronization predicted greater social and sensory symptoms. Directing attention to auditory stimuli may be associated with more typical neural auditory processing in autism. [ABSTRACT FROM AUTHOR]

Background: Magnetoencephalography (MEG) is a non-invasive imaging technique for directly measuring the external magnetic field generated from synchronously activated pyramidal neurons in the brain. The optically pumped magnetometer (OPM) is known for its less expensive, non-cryogenic, movable and user-friendly custom-design provides the potential for a change in functional neuroimaging based on MEG. Methods: An array of OPMs covering the opposite sides of a subject's head is placed inside a magnetically shielded room (MSR) and responses evoked from the auditory cortices are measured. Results: High signal-to-noise ratio auditory evoked response fields (AEFs) were detected by a wearable OPM-MEG system in a MSR, for which a flexible helmet was specially designed to minimize the sensor-to-head distance, along with a set of bi-planar coils developed for background field and gradient nulling. Neuronal current sources activated in AEF experiments were localized and the auditory cortices showed the highest activities. Performance of the hybrid optically pumped magnetometer-magnetoencephalography/electroencephalography (OPM-MEG/EEG) system was also assessed. Conclusions: The multi-channel OPM-MEG system performs well in a custom built MSR equipped with bi-planar coils and detects human AEFs with a flexible helmet. Moreover, the similarities and differences of auditory evoked potentials (AEPs) and AEFs are discussed, while the operation of OPM-MEG sensors in conjunction with EEG electrodes provides an encouraging combination for the exploration of hybrid OPM-MEG/EEG systems. [ABSTRACT FROM AUTHOR]

Background Sensory suppression occurs when hearing one's self-generated voice, as opposed to passively listening to one's own voice. Quality changes in sensory feedback to the self-generated voice can increase attentional control. These changes affect the self-other voice distinction and might lead to hearing voices in the absence of an external source (ie, auditory verbal hallucinations). However, it is unclear how changes in sensory feedback processing and attention allocation interact and how this interaction might relate to hallucination proneness (HP). Study Design Participants varying in HP self-generated (via a button-press) and passively listened to their voice that varied in emotional quality and certainty of recognition—100% neutral, 60%–40% neutral-angry, 50%–50% neutral-angry, 40%–60% neutral-angry, 100% angry, during electroencephalography (EEG) recordings. Study Results The N1 auditory evoked potential was more suppressed for self-generated than externally generated voices. Increased HP was associated with (1) an increased N1 response to the self- compared with externally generated voices, (2) a reduced N1 response for angry compared with neutral voices, and (3) a reduced N2 response to unexpected voice quality in sensory feedback (60%–40% neutral-angry) compared with neutral voices. Conclusions The current study highlights an association between increased HP and systematic changes in the emotional quality and certainty in sensory feedback processing (N1) and attentional control (N2) in self-voice production in a nonclinical population. Considering that voice hearers also display these changes, these findings support the continuum hypothesis. [ABSTRACT FROM AUTHOR]