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The ability to detect a silent gap within a sound is critical for accurate speech perception, and gap detection has been shown to have an extended developmental trajectory. In certain conditions, the detectability of the gap decreases as the gap is placed closer to the beginning of the signal. Early in development, the detection of gaps shortly after signal onset may be especially difficult due to immaturities in the encoding and perception of rapidly changing sounds. The present study explored the development of gap detection from age 8 to 19 years, specifically when the temporal placement of the gap varied. Performance improved with age for all temporal placements of the gap, demonstrating a gradual maturation of gap detection abilities throughout adolescence. Younger adolescents did not benefit from increasing gap onset times, while older adolescents’ thresholds gradually improved as gap onset time lengthened. Regardless of age, listeners learned between the two testing days but did not improve within days. Younger adolescents had poorer thresholds for the last block of testing on the second day, returning to baseline performance despite learning between days. These data support earlier studies showing that gaps are harder to detect near stimulus onset and confirm that gap detection abilities continue to mature into adolescence. The data also suggest that younger adolescents do not receive the same benefit of increasing gap onset time and respond differently to repeated testing than older adolescents and young adults.

The perception of temporally changing auditory signals has a gradual developmental trajectory. Speech is a time-varying signal, and slow changes in speech (filtered at 0-4 Hz) are preferentially processed by the right hemisphere, while the left extracts faster changes (filtered at 22-40 Hz). This work examined the ability of 8- to 19-year-olds to both perceive and learn to perceive filtered speech presented diotically for each filter type (low vs high) and dichotically for preferred or non-preferred laterality. Across conditions, performance improved with increasing age, indicating that the ability to perceive filtered speech continues to develop into adolescence. Across age, performance was best when both bands were presented dichotically, but with no benefit for presentation to the preferred hemisphere. Listeners thus integrated slow and fast transitions between the two ears, benefitting from more signal information, but not in a hemisphere-specific manner. After accounting for potential ceiling effects, learning was greatest when both bands were presented dichotically. These results do not support the idea that cochlear implants could be improved by providing differentially filtered information to each ear. Listeners who started with poorer performance learned more, a factor which could contribute to the positive cochlear implant outcomes typically seen in younger children.

Purpose The aim of the study was to compare comprehension of spectrally degraded (noise-vocoded [NV]) speech and perceptual learning of NV speech between adolescents and young adults and examine the role of phonological processing and executive functions in this perception. Method Sixteen younger adolescents (11–13 years), 16 older adolescents (14–16 years), and 16 young adults (18–22 years) listened to 40 NV sentences and repeated back what they heard. They also completed tests assessing phonological processing and a variety of executive functions. Results Word-report scores were generally poorer for younger adolescents than for the older age groups. Phonological processing also predicted initial word-report scores. Learning (i.e., improvement across training times) did not differ with age. Starting performance and processing speed predicted learning, with greater learning for those who started with the lowest scores and those with faster processing speed. Conclusions Degraded (NV) speech comprehension is not mature even by early adolescence; however, like adults, adolescents are able to improve their comprehension of degraded speech with training. Thus, although adolescents may have initial difficulty in understanding degraded speech or speech as presented through hearing aids or cochlear implants, they are able to improve their perception with experience. Processing speed and phonological processing may play a role in degraded speech comprehension in these age groups.

The letter is about a community of scientists who have personally experienced the barriers imposed by hearing loss. Community represents an alternative model of distributed academic peer networking that has grown and evolved over the past 25 years. This model has enabled members to overcome personal and professional barriers while promoting the inclusion of numerous D/HH scientists at all levels of biomedical research.

Purpose We investigated whether perceptual learning of noise-vocoded (NV) speech is specific to a particular talker or accent. Method Four groups of listeners ( n = 18 per group) were first trained by listening to 20 NV sentences that had been recorded by a talker with either the same native accent as the listeners or a different regional accent. They then heard 20 novel NV sentences from either the native- or nonnative-accented talker (test), in a 2 × 2 (Training Talker per Accent × Test Talker per Accent) design. Results Word-report scores at test for participants trained and tested with the same (native- or nonnative-accented) talker did not differ from those for participants trained with 1 talker per accent and tested on another. Conclusions Learning of NV speech generalized completely between talkers. Two additional experiments confirmed this result. Thus, when listeners are trained to understand NV speech, they are not learning talker- or accent-specific features but instead are learning how to use the information available in the degraded signal. The results suggest that people with cochlear implants, who experience spectrally degraded speech, may not be too disadvantaged if they learn to understand speech through their implant by listening primarily to just 1 other talker, such as a spouse.

Many perceptual abilities differ between the sexes. Because these sex differences have been documented almost exclusively in adults, they have been attributed to sex-specific neural circuitry that emerges during development and is maintained in the mature perceptual system. To investigate whether behavioral sex differences in perception can also have other origins, we compared performance between males and females ranging in age from 8 to 30 years on auditory temporal-interval discrimination and tone-in-noise detection tasks on which there are no sex differences in adults. If sex differences in perception arise only from the establishment and subsequent maintenance of sex-specific neural circuitry, there should be no sex differences during development on these tasks. In contrast, sex differences emerged in adolescence but resolved by adulthood on two of the six conditions, with signs of a similar pattern on a third condition. In each case, males reached mature performance earlier than females, resulting in a sex difference in the interim. These results suggest that sex differences in perception may arise from differences in the maturational timing of common circuitry used by both sexes. They also imply that sex differences in perceptual abilities may be more prevalent than previously thought based on adult data alone.

Understanding speech in the presence of background sound can be challenging for older adults. Speech comprehension in noise appears to depend on working memory and executive-control processes (e.g., Heald & Nusbaum, 2014), and their augmentation through training may have rehabilitative potential for age-related hearing loss. We examined the efficacy of adaptive working-memory training (Cogmed; Klingberg, Forssberg & Westerberg, 2002) in 24 older adults, assessing generalization to other working-memory tasks (near-transfer) and to other cognitive domains (far-transfer) using a cognitive test battery, including the Reading Span test, sensitive to working memory (e.g., Daneman and Carpenter 1980). We also assessed far transfer to speech-in-noise performance, including a closed-set sentence task (Kidd, Best & Mason 2005). To examine the effect of cognitive training on benefit obtained from semantic context, we also assessed transfer to open-set sentences; half were semantically coherent (high-context) and half were semantically anomalous (low-context). Subjects completed 25 sessions (0.5-1 hour each; 5 sessions/week) of both adaptive working memory training and placebo training over 10 weeks in a crossover design. Subjects’ scores on the adaptive working-memory training tasks improved as a result of training. However, training did not transfer to other working memory tasks, nor to tasks recruiting other cognitive domains. We did not observe any training-related improvement in speech-in-noise performance. Measures of working memory correlated with the intelligibility of low-context, but not high-context, sentences, suggesting that sentence context may reduce the load on working memory. The Reading Span test significantly correlated only with a test of visual episodic memory, suggesting that the Reading Span test is not a pure-test of working memory, as is commonly assumed.

Humans are able to adapt to unfamiliar forms of speech (such as accented, time-compressed, or noise-vocoded speech) quite rapidly. Can such perceptual learning occur when attention is directed away from the speech signal? Here, participants were simultaneously exposed to noise-vocoded sentences, auditory distractors, and visual distractors. One group attended to the speech, listening to each sentence and reporting what they heard. Two other groups attended to either the auditory or visual distractors, performing a target-detection task. Only the attend-speech group benefited from the exposure when subsequently reporting noise-vocoded sentences. Thus, attention to noise-vocoded speech appears necessary for learning.

While it is commonly held that the capacity to learn is greatest in the young, there have been few direct comparisons of the response to training across age groups. Here, adolescents (11–17 years, n = 20) and adults (≥18 years, n = 11) practiced detecting a backward-masked tone for ∼1 h/day for 10 days. Nearly every adult, but only half of the adolescents improved across sessions, and the adolescents who learned did so more slowly than adults. Nevertheless, the adolescent and adult learners showed the same generalization pattern, improving on untrained backward- but not forward- or simultaneous-masking conditions. Another subset of adolescents (n = 6) actually got worse on the trained condition. This worsening, unlike learning, generalized to an untrained forward-masking, but not backward-masking condition. Within sessions, both age groups got worse, but the worsening was greater for adolescents. These maturational changes in the response to training largely followed those previously reported for temporal-interval discrimination. Overall, the results suggest that late-maturing processes affect the response to perceptual training and that some of these processes may be shared between tasks. Further, the different developmental rates for learning and generalization, and different generalization patterns for learning and worsening imply that learning, generalization, and worsening may have different origins.

Adults can improve their performance on many perceptual tasks with training, but when does the response to training become mature? To investigate this question, we trained 11-year-olds, 14-year-olds and adults on a basic auditory task (temporal-interval discrimination) using a multiple-session training regimen known to be effective for adults. The adolescents all began with performance in the adult range. However, while all of the adults improved across sessions, none of the 11-year-olds and only half of the 14-year-olds did. The adolescents who failed to learn did so even though the 10-session training regimen provided twice the number of sessions required by adults to reach asymptotic performance. Further, over the course of each session, the performance of the adults was stable but that of the adolescents, including those who learned, deteriorated. These results demonstrate that the processes that underlie perceptual learning can continue to develop well into adolescence.

Individuals with reading disorders have difficulty reading despite having normal intelligence. Many also exhibit a number of auditory perceptual deficits. According to one proposal, these deficits arise because perceptual development in these individuals is delayed in childhood and then halted, for skills on which improvements would normally continue into adolescence, around age 10 (presumably due to brain changes associated with puberty). If so, perceptual skills with long developmental courses should be impaired in adults with reading disorders. While perceptual development is typically examined through naive performance, this prediction was tested here using a perceptual‐learning paradigm. Ten adults with reading disorders were trained on a temporal‐interval discrimination task using a multiple‐session training regimen known to yield learning reliably in adults, but rarely in adolescents [Huyck and Wright, Developmental Science (in press). Seven of the ten did not improve with training. Thus, the response to training in the adults with reading disorders more closely resembled that of adolescent than of adult controls. This result is consistent with the idea that perceptual development may be delayed and then halted in individuals with reading disorders and highlights prolonged maturational changes in a perceptual skill other than naive performance.

Between infancy and adulthood, performance on auditory perceptual tasks becomes both better on average and more consistent. However, little is known about the relationship between these two aspects of performance during development. This issue was investigated by using a cross‐sectional design to estimate the ages at which measures of average performance (the mean of multiple threshold estimates for each listener) and performance consistency (the within‐listener standard deviation of those estimates) became adultlike on two temporal‐interval discrimination and four masking conditions (ages: 8–30 years, n=50–142 per condition). Average performance became mature before consistency on two simultaneous‐masking conditions, after consistency on two nonsimultaneous masking conditions (backward and forward), and at the same time as consistency on the two temporal‐interval discrimination conditions. In addition, on five of the six conditions, males matured more quickly than females on both measures or on consisten...

Recent evidence suggests that the development of naive performance on some auditory perceptual tasks can continue well into adolescence. Of interest here was whether there are sex differences in the maturation rate on three such tasks, temporal‐interval discrimination, tone detection in forward masking, and tone detection in backward masking. To investigate this issue, performance was compared between males and females in multiple age groups on these three tasks (n per sex in each age group=9–20). There were no sex differences for backward masking. However, males reached adult‐like performance earlier than females on the other two tasks: forward masking (males at ∼12 years, females at ∼15 years) and temporal‐interval discrimination (males at 14 years, females at >14 years, on each of three separate conditions). Surprisingly, the male advantage occurred only during adolescence. Thus, on two of the three late‐developing auditory abilities examined, males matured more quickly than females, but did not differ...