Time-compressed Sentences Research Articles

Visual Processing Impairment in Children With Suspected Auditory Processing Disorder: A Transdisciplinary Dimensional Approach to Diagnosis.

The purpose of this study is to explore the utility of impairment(s) in language (LI), manual dexterity (IMD), and visual perceptual skills (IVPS) as a reference standard for diagnosing auditory processing disorder (APD). Data from 104 participants with suspected APD (males = 57, females = 47; 6-16 years) were retrospectively analyzed. Index auditory processing (AP) tests included Auditory Figure Ground 0 dB, Competing Words-Directed Ear (CW-DE), and Time-Compressed Sentences (TCS). General Communication Composite (GCC) of the Children's Communication Checklist-2, manual dexterity (MD) component of the Movement Assessment Battery for Children-Second Edition, and Test for Visual Perceptual Skills-Third Edition (TVPS-3) were used to identify LI, IMD, and IVPS, respectively. Eighty-one (77.8%), 58 (55.8%), and 37 (35.6%) participants had LI, IVPS, and IMD, respectively. Four factors explaining 67.69% of the variance were extracted. TVPS-3 (except visual closure [VClo]) represented the first; AFG 0, VClo, and MD the second; CW-DE and GCC the third; and TCS the fourth. APD diagnosed by combining AP tests and comorbidities had better accuracy compared to AP tests alone. The combined approach had overall diagnostic accuracy of 92.2%, 88.4%, and 81.7% for the 9th, 5th, and 2nd percentile AP test cutoffs, respectively. First-order AP tests in this study were related to language, MD, and visual perceptual skills. Given the overlap of LI, IMD, and IVPS with impaired AP, these comorbidities are an effective reference standard for APD. APD can be diagnosed following failing one AP test if one or more comorbidities exist. Ninth percentile AP test cutoff had better diagnostic accuracy compared to the currently used 2nd percentile cutoff.

Neural oscillations track natural but not artificial fast speech: Novel insights from speech-brain coupling using MEG

Neural oscillations contribute to speech parsing via cortical tracking of hierarchical linguistic structures, including syllable rate. While the properties of neural entrainment have been largely probed with speech stimuli at either normal or artificially accelerated rates, the important case of natural fast speech has been largely overlooked. Using magnetoencephalography, we found that listening to naturally-produced speech was associated with cortico-acoustic coupling, both at normal (∼6 syllables/s) and fast (∼9 syllables/s) rates, with a corresponding shift in peak entrainment frequency. Interestingly, time-compressed sentences did not yield such coupling, despite being generated at the same rate as the natural fast sentences. Additionally, neural activity in right motor cortex exhibited stronger tuning to natural fast rather than to artificially accelerated speech, and showed evidence for stronger phase-coupling with left temporo-parietal and motor areas. These findings are highly relevant for our understanding of the role played by auditory and motor cortex oscillations in the perception of naturally produced speech.

Relationship between Verbal and Nonverbal Tests of Auditory Temporal Processing.

Audiologists may choose to evaluate auditory temporal processing in assessing auditory processing abilities. Some may decide to use measures of nonverbal stimuli such as tonal or noise gap detection. Others may decide to use verbal measures such as time compressed sentences (TCS). Many may choose to use both. Since people typically come to audiologists for auditory processing testing complaining of problems processing verbal stimuli, the question arises whether measures of nonverbal stimuli provide evidence regarding a person's abilities to processing verbal stimuli. That is, are there significant correlations between measures of verbal stimuli and nonverbal stimuli that are used to evaluate auditory temporal processing? The present investigation is an exploratory study using file review of 104 people seen for routine auditory processing evaluations by the authors. A file review was completed based on data from 104 people seen for auditory processing evaluations. The data from these 104 files were used to evaluate whether there are any correlations between verbal and nonverbal measures of auditory temporal processing. The verbal measure used was the TCS subtest of the SCAN-3 while the nonverbal measures included the gap detection screening from the SCAN-3 as well as the gaps-in-noise measures. Results from these tests were compared to determine whether any significant correlations were found based on results from Pearson product moment correlational analyses. None of the nonverbal measures were found to have a significant correlation with the TCS test findings based on the Pearson correlations used to analyze the data. Results indicate that there are no significant correlations (relationships) between measures of auditory temporal processing using nonverbal stimuli versus verbal stimuli based on the tests used in the present investigation. These findings lead to a conclusion that tests using nonverbal stimuli are measuring different auditory processes than the measure of verbal stimuli used in the present investigation. Since people typically come complaining about understanding verbal input, it is concluded that audiologists should use some verbal measure of auditory temporal processing in their auditory processing test battery.

Effects of stimulus repetition and training schedule on the perceptual learning of time-compressed speech and its transfer.

Perceptual learning can facilitate the recognition of hard-to-perceive (e.g., time-compressed or spectrally-degraded) speech. Although the learning induced by training with time-compressed speech is robust, previous findings suggest that intensive training yields learning that is partially specific to the items encountered during practice. Here, we asked whether three parameters of the training procedure - the overall number of training trials (training intensity), how these trials are distributed across sessions, and the number of semantically different items encountered during training (set size) - influence learning and transfer. Different groups of participants (69 normal-hearing young adults; nine to 11 participants/group) completed different training protocols (or served as an untrained control group) and tested on the recognition of time-compressed sentences taken from the training set (learning), new time-compressed sentences presented by the trained talker (semantic transfer), and time-compressed sentences taken from the training set but presented by a different talker (acoustic transfer). Compared to untrained listeners, all training protocols yielded both learning and transfer. More intense training resulted in greater item-specific learning and greater acoustic transfer than less intense training with the same number of training sessions. Training on a smaller set size (i.e., greater token repetition during training) also resulted in greater acoustic transfer, whereas distributing practice over a number of sessions improved semantic transfer. Together, these data suggest that whereas practice on a small set that results in stimulus repetition during training is not harmful for learning, distributed training can support transfer to new stimuli, perhaps because it provides multiple opportunities to consolidate learning.

Effect of compression release time of a hearing aid on sentence recognition and the quality judgment of speech.

Context:The sentence recognition score and quality of speech differ when hearing aid compression is set at different release times at different signal to noise ratios (SNRs) for the normal and compressed rate of sentences.Aims:To investigate the effect of amplitude-compression release time of a hearing aid on sentence recognition and quality judgment: (1) for normal rate and time-compressed sentences (2) in quiet and noisy conditions.Settings and Design:A post-test repeated measures design.Methods and Material:We recruited fifteen adult participants with bilateral sensorineural hearing loss in each group, the younger (35–45 years), and the older ones (60–70 years). A gap detection test assessed temporal processing ability. We used three compression settings, fast-acting, slow-acting, and linear. Sentence recognition and quality and envelope difference index in normal and altered rates were assessed in quiet and in noise at these three compression settings.Statistical analysis used:A repeated measure ANOVA.Results:We found a significant improvement in recognition of sentences at a normal rate in slow compression release time, compared to fast and linear gain settings at each SNR. Similar results were observed for sentences compressed at the rate of 35% in quiet and +10 dB SNR. Further, the participants preferred the quality of speech in quiet with the hearing aid set to slow compared to fast compression release time. The benefit from the slow compression release time was higher than either linear or fast compression release time on sentence recognition. Further, we saw that there was a negative impact on sentence recognition at 3 dB SNR (normal-rate) and in quiet (35% compression rate) in older adults.Conclusions:The slow compression release time in a hearing aid is superior to the fast one in noisy conditions and also with higher subjective ratings of speech quality in quiet.

The relationship between speech recognition in noise and non-speech recognition in noise test performances: Implications for central auditory processing disorders testing

BackgroundAccording to the American Academy of Audiology, a recommendation for frequency-modulation systems may be based upon performances on speech perception tests that do not include background noise. PurposeThe primary purpose of this study was to evaluate the presumption that non-speech recognition in noise test results are related to speech recognition in noise ability for a group of young adults. Research designPerformances on the non-speech recognition in noise tests included in the SCAN-3:A test battery were compared to speech recognition in noise performances as measured with the auditory figure ground subtest of the SCAN-3:A and the Hearing in Noise Test. Study sampleFifty-four young, native speakers of American English with normal pure-tone thresholds participated in the study. Data collection and analysisFor the purposes of this study, the SCAN-3:A raw scores were used. The Hearing in Noise Test was administered in a simulated soundfield environment under headphones. The Spearman rho statistic was used to determine the relationships between non-speech recognition in noise vs. speech recognition in noise test results. ResultsNo significant relationships were found between the auditory figure-ground results and any of the non-speech recognition in noise subtest performances. Modest but statistically significant relationships were found between the Hearing in Noise Test Composite scores vs. the competing words-directed ear and the time compressed sentences subtests of the SCAN-3:A. ConclusionOf the four non-speech recognition in noise subtests that were evaluated, only the competing words-directed ear and the time-compressed sentences performances were significantly correlated to the Composite scores of the Hearing in Noise Test. The results demonstrated a limited external validity for two of the four non-SRN tests for the determination of SRN ability.

Time-Compressed Speech Identification Is Predicted by Auditory Neural Processing, Perceptuomotor Speed, and Executive Functioning in Younger and Older Listeners.

Older adults typically have difficulty identifying speech that is temporally distorted, such as reverberant, accented, time-compressed, or interrupted speech. These difficulties occur even when hearing thresholds fall within a normal range. Auditory neural processing speed, which we have previously found to predict auditory temporal processing (auditory gap detection), may interfere with the ability to recognize phonetic features as they rapidly unfold over time in spoken speech. Further, declines in perceptuomotor processing speed and executive functioning may interfere with the ability to track, access, and process information. The current investigation examined the extent to which age-related differences in time-compressed speech identification were predicted by auditory neural processing speed, perceptuomotor processing speed, and executive functioning. Groups of normal-hearing (up to 3000Hz) younger and older adults identified 40, 50, and 60% time-compressed sentences. Auditory neural processing speed was defined as the P1 and N1 latencies of click-induced auditory-evoked potentials. Perceptuomotor processing speed and executive functioning were measured behaviorally using the Connections Test. Compared to younger adults, older adults exhibited poorer time-compressed speech identification and slower perceptuomotor processing. Executive functioning, P1 latency, and N1 latency did not differ between age groups. Time-compressed speech identification was independently predicted by P1 latency, perceptuomotor processing speed, and executive functioning in younger and older listeners. Results of model testing suggested that declines in perceptuomotor processing speed mediated age-group differences in time-compressed speech identification. The current investigation joins a growing body of literature suggesting that the processing of temporally distorted speech is impacted by lower-level auditory neural processing and higher-level perceptuomotor and executive processes.

Auditory processing and neuropsychological profiles of children with functional hearing loss

ObjectivesThis paper compares structured history, auditory processing abilities and neuropsychological findings of children with functional hearing loss (FHL) to those with suspected auditory processing disorder without FHL (control). The main aim was to evaluate the value of a holistic assessment protocol for FHL used in a routine pediatric audiology clinic. The protocol incorporated a commercially available test battery for auditory processing disorder (APD), non-verbal intelligence (NVIQ) and tools to screen for common co-existing neurodevelopmental conditions such as attention deficit hyperactivity disorder (ADHD), language impairment (LI) and developmental coordination disorder (DCD). The outcome of such holistic assessment was expected to help in understanding the nature of FHL and to provide individualized support to mitigate their difficulties. MethodsThis retrospective study compared two groups, 40 children (M = 17, F = 23) in each group between seven and sixteen years of age, one group with a history of FHL and the other with suspected APD without FHL (control). The groups were matched against age, gender, hand use, diagnosis of APD or non-APD (31 with APD and 9 without APD in each group) and non-verbal intelligence. All the children were healthy English speaking children attending mainstream schools with no middle or inner ear abnormalities. Structured history was obtained from parents regarding different nonacademic and academic concerns. The SCAN-3:C and SCAN-3:A test batteries were used to assess auditory processing abilities; Lucid Ability test for NVIQ; Children's Communication Checklist-2 (CCC-2) for language ability; Swanson Nolan and Pelham-IV Rating Scale (SNAP-IV) for ADHD; and the manual dexterity components of the Movement Assessment Battery for Children-2 (MABC-2) as a screening tool for DCD. ResultsAbout 60% of children in both the groups had concerns regarding listening in noisy background. In the history, poor attention was reported in 45% of children in the FHL group compared to 82.5% in the control group (p < 0.01). Hyperacusis was present in 35% of children in the FHL group and in 62% of children in the control group (p < 0.05). Concerns about overall academic abilities were present in 59% of children in the FHL group and 75% of the controls (p > 0.05). Only 15% of children in the FHL group had concerns with numeracy skills in contrast to 41% of the controls (p < 0.05). Significantly fewer (p < 0.01) children in the FHL group (41%) received additional support at school than the controls (75%). Fewer children performed poorly in Filtered Words (FW) test of the SCAN-3 batteries, 30% in the FHL group and 17.5% in the control group, in contrast to Auditory Figure Ground 0 (AFG0), 85% in FHL and 80% in the control group. The number of children performing poorly in AFG0 was significantly higher compared to all the other SCAN-3 tests in FHL (P < 0.05), in contrast to FW and Competing Sentences (CS) only in the control group (p < 0.05). The control group had higher prevalence of atypical ear advantage (AEA) in left directed Competing Words (CW) (32.5%) and Time Compressed Sentences (TCS) (32.5%) compared to FW (7.5%). In contrast, FHL group had higher prevalence of AEA in AFG0 (48.7%) compared to CS (21%). High proportions of children in both the groups had LI (80% in FHL and 82.5% in the control group), with significantly lower (p < 0.05) levels of ADHD symptoms in the FHL group (39.5%) compared to the control group (72.5%). Impaired manual dexterity was present in 30.7% of children in FHL group and 47.5% in the controls. ConclusionsThe prevalences of APD and language impairment are high compared to ADHD symptoms in children with FHL, and holistic assessment is recommended. Despite some similarities in the auditory and neuropsychological profiles between children with FHL and those with suspected APD without FHL some differences were noted. The results suggest that children with FHL have genuine difficulties that need to be identified and addressed. Future research is required to identify the neural pathways which could explain the similarities and dissimilarities between the two groups.

Processing speed and age predict recognition of spectro-temporally degraded speech

Cochlear implants (CIs) provide a listener with the temporal envelope of an acoustic signal, but not the spectral fine structure. Speech recognition performance is highly variable among individuals and is often assessed clinically in ideal conditions (over-articulated, clean speech) rather than real-world listening environments. This study examined the effects of age and processing speed on understanding of time-compressed speech by listeners with normal hearing (NH) presented with vocoded speech of varying spectral resolution and listeners with CIs. NH listeners repeated sentences that had been time-compressed to varying degrees (no compression, 20%, 40%, or 60% time compression ratios) and then noise vocoded with various channels (4, 8, or 16 channels or unprocessed), while CI participants repeated unprocessed time-compressed sentences. Performance of age-matched NH listeners on the 4-channel vocoded speech most closely matched CI listeners’ performance at each level of time-compression. For NH listeners, age effects were observed on conditions featuring time compression and reduced spectral resolution. Both NH and CI listener groups showed a significant interaction between age and time compression. As difficulty increased (greater time compression for all, fewer channels for NH), cognitive measures of processing speed were correlated with speech recognition performance across all age and listening groups.

The effects of exposure and training on the perception of time-compressed speech in native versus nonnative listeners.

The present study investigated the effects of language experience on the perceptual learning induced by either brief exposure to or more intensive training with time-compressed speech. Native (n = 30) and nonnative (n = 30) listeners were each divided to three groups with different experiences with time-compressed speech: A trained group who trained on the semantic verification of time-compressed sentences for three sessions, an exposure group briefly exposed to 20 time-compressed sentences, and a group of naive listeners. Recognition was assessed with three sets of time-compressed sentences intended to evaluate exposure-induced and training-induced learning as well as across-token and across-talker generalization. Learning profiles differed between native and nonnative listeners. Exposure had a weaker effect in nonnative than in native listeners. Furthermore, native and nonnative trained listeners significantly outperformed their untrained counterparts when tested with sentences taken from the training set. However, only trained native listeners outperformed naive native listeners when tested with new sentences. These findings suggest that the perceptual learning of speech is sensitive to linguistic experience. That rapid learning is weaker in nonnative listeners is consistent with their difficulties in real-life conditions. Furthermore, nonnative listeners may require longer periods of practice to achieve native-like learning outcomes.

Auditory "bubbles": Efficient classification of the spectrotemporal modulations essential for speech intelligibility.

Speech intelligibility depends on the integrity of spectrotemporal patterns in the signal. The current study is concerned with the speech modulation power spectrum (MPS), which is a two-dimensional representation of energy at different combinations of temporal and spectral (i.e., spectrotemporal) modulation rates. A psychophysical procedure was developed to identify the regions of the MPS that contribute to successful reception of auditory sentences. The procedure, based on the two-dimensional image classification technique known as "bubbles" (Gosselin and Schyns (2001). Vision Res. 41, 2261-2271), involves filtering (i.e., degrading) the speech signal by removing parts of the MPS at random, and relating filter patterns to observer performance (keywords identified) over a number of trials. The result is a classification image (CImg) or "perceptual map" that emphasizes regions of the MPS essential for speech intelligibility. This procedure was tested using normal-rate and 2×-time-compressed sentences. The results indicated: (a) CImgs could be reliably estimated in individual listeners in relatively few trials, (b) CImgs tracked changes in spectrotemporal modulation energy induced by time compression, though not completely, indicating that "perceptual maps" deviated from physical stimulus energy, and

Diffusion Tensor Imaging Reveals White Matter Microstructure Correlations With Auditory Processing Ability

Correlation of white matter microstructure with various cognitive processing tasks and with overall intelligence has been previously demonstrated. We investigate the correlation of white matter microstructure with various higher-order auditory processing tasks, including interpretation of speech-in-noise, recognition of low-pass frequency filtered words, and interpretation of time-compressed sentences at two different values of compression. These tests are typically used to diagnose auditory processing disorder (APD) in children. Our hypothesis is that correlations between white matter microstructure in tracts connecting the temporal, frontal, and parietal lobes, as well as callosal pathways, will be seen. Previous functional imaging studies have shown correlations between activation in temporal, frontal, and parietal regions from higher-order auditory processing tasks. In addition, we hypothesize that the regions displaying correlations will vary according to the task because each task uses a different set of skills. Diffusion tensor imaging (DTI) data were acquired from a cohort of 17 normal-hearing children aged 9 to 11 yrs. Fractional anisotropy (FA), a measure of white matter fiber tract integrity and organization, was computed and correlated on a voxelwise basis with performance on the auditory processing tasks, controlling for age, sex, and full-scale IQ. Divergent correlations of white matter FA depending on the particular auditory processing task were found. Positive correlations were found between FA and speech-in-noise in white matter adjoining prefrontal areas and between FA and filtered words in the corpus callosum. Regions exhibiting correlations with time-compressed sentences varied depending on the degree of compression: the greater degree of compression (with the greatest difficulty) resulted in correlations in white matter adjoining prefrontal (dorsal and ventral), whereas the smaller degree of compression (with less difficulty) resulted in correlations in white matter adjoining audiovisual association areas and the posterior cingulate. Only the time-compressed sentences with the lowest degree of compression resulted in positive correlations in the centrum semiovale; all the other tasks resulted in negative correlations. The dependence of performance on higher-order auditory processing tasks on brain anatomical connectivity was seen in normal-hearing children aged 9 to 11 yrs. Results support a previously hypothesized dual-stream (dorsal and ventral) model of auditory processing, and that higher-order processing tasks rely less on the dorsal stream related to articulatory networks and more on the ventral stream related to semantic comprehension. Results also show that the regions correlating with auditory processing vary according to the specific task, indicating that the neurological bases for the various tests used to diagnose APD in children may be partially independent.

Perceptual learning of time-compressed and natural fast speech

Speakers vary their speech rate considerably during a conversation, and listeners are able to quickly adapt to these variations in speech rate. Adaptation to fast speech rates is usually measured using artificially time-compressed speech. This study examined adaptation to two types of fast speech: artificially time-compressed speech and natural fast speech. Listeners performed a speeded sentence verification task on three series of sentences: normal-speed sentences, time-compressed sentences, and natural fast sentences. Listeners were divided into two groups to evaluate the possibility of transfer of learning between the time-compressed and natural fast conditions. The first group verified the natural fast before the time-compressed sentences, while the second verified the time-compressed before the natural fast sentences. The results showed transfer of learning when the time-compressed sentences preceded the natural fast sentences, but not when natural fast sentences preceded the time-compressed sentences. The results are discussed in the framework of theories on perceptual learning. Second, listeners show adaptation to the natural fast sentences, but performance for this type of fast speech does not improve to the level of time-compressed sentences.

Speech recognition and working memory capacity in young-elderly listeners: Effects of hearing sensitivity.

Young normal-hearing listeners and young-elderly listeners between 55 and 65 years of age, ranging from near-normal hearing to moderate hearing loss, were compared using different speech recognition tasks (consonant recognition in quiet and in noise, and time-compressed sentences) and working memory tasks (serial word recall and digit ordering). The results showed that the group of young-elderly listeners performed worse on both the speech recognition and working memory tasks than the young listeners. However, when pure-tone audiometric thresholds were used as a covariate variable, the significant differences between groups disappeared. These results support the hypothesis that sensory decline in young-elderly listeners seems to be an important factor in explaining the decrease in speech processing and working memory capacity observed at these ages.

On-line plasticity in spoken sentence comprehension: Adapting to time-compressed speech

Listeners show remarkable flexibility in processing variation in speech signal. One striking example is the ease with which they adapt to novel speech distortions such as listening to someone with a foreign accent. Behavioural studies suggest that significant improvements in comprehension occur rapidly — often within 10–20 sentences. In the present experiment, we investigate the neural changes underlying on-line adaptation to distorted speech using time-compressed speech. Listeners performed a sentence verification task on normal-speed and time-compressed sentences while their neural responses were recorded using fMRI. The results showed that rapid learning of the time-compressed speech occurred during presentation of the first block of 16 sentences and was associated with increased activation in left and right auditory association cortices and in left ventral premotor cortex. These findings suggest that the ability to adapt to a distorted speech signal may, in part, rely on mapping novel acoustic patterns onto existing articulatory motor plans, consistent with the idea that speech perception involves integrating multi-modal information including auditory and motoric cues.

Recognition of Time-Compressed and Natural Speech With Selective Temporal Enhancements by Young and Elderly Listeners

The goal of this experiment was to determine whether selective slowing of speech segments improves recognition performance by young and elderly listeners. The hypotheses were (a) the benefits of time expansion occur for rapid speech but not for natural-rate speech, (b) selective time expansion of consonants produces greater score increments than other forms of selective time expansion, and (c) older listeners benefit from time expansion of speech Participants (n=10-16 per group) were younger and older adults with normal hearing or with hearing loss. A repeated-measures design was used to assess recognition of sentence-length stimuli presented in 2 baseline speech rates: natural and 50% time compression. Selective time expansion of consonants, vowels, or pauses was applied to the natural-rate and time-compressed sentence-length stimuli. Listeners showed excellent performance for natural-rate speech, regardless of time-expansion method. Recognition was significantly poorer for the time-compressed sentences, but performance by elderly listeners and listeners with hearing loss improved with selective time expansion, particularly when applied to consonant segments. The findings support the hypothesis that older listeners and listeners with hearing impairment benefit from selective time expansion of consonants applied to rapid speech, without a corresponding decrement when applied to normal-rate speech.

Effects of stimulus variability and adult aging on adaptation to time-compressed speech

With as few as 10-20 sentences of exposure, listeners are able to adapt to speech that is highly distorted compared to that which is encountered in everyday conversation. The current study examines the extent to which adaptation to time-compressed speech can be impeded by disrupting the continuity of the exposure sentences, and whether this differs between young and older adult listeners when they are equated for starting accuracy. In separate sessions conducted one week apart, the degree of adaptation was assessed in four exposure conditions, all of which involved exposure to the same number of time-compressed sentences. A continuous exposure condition involved presentation of the time-compressed sentences without interruption. Two alternation conditions alternated time-compressed speech and uncompressed speech by single sentences or groups of four sentences. A fourth condition presented sentences that were separated by a period of silence but no uncompressed speech. For all conditions, neither young nor older adults' overall level of learning was influenced by disruptions to the exposure sentences. In addition, participants' performance showed reliable improvement across the first and subsequent sessions. These results support robust learning mechanisms in speech perception that remain functional throughout the lifespan.

Sequencing versus Nonsequencing Working Memory in Understanding of Rapid Speech by Older Listeners

The goal of this study was to identify specific neurocognitive deficits that are associated with older listeners' difficulty understanding rapid speech. Older listeners performed speech recognition tests comprised of time-compressed sentences with and without context, and on a neurocognitive battery aimed specifically at testing working memory, processing speed, and attention. A principle component analysis identified three main cognitive components as follows: a sequencing working memory (WM-S) component, a nonsequencing working memory (WM-NS) component, and a processing speed (PS) component. Each of the cognitive component scores was divided into high, mid, and low categories. Sentence performance of the cognitive subgroups was compared within each component. The results showed that, with hearing loss and age accounted for, the cognitive score groups differed similarly on the sentence condition scores also at 50 and 60% time compression, particularly on the subgroups of the WM-S component. The results suggest that deficits in a separate working memory function identified as sequencing were associated with differences in ability to understand time-compressed speech in this study.

Dissociations in Perceptual Learning Revealed by Adult Age Differences in Adaptation to Time-Compressed Speech.

When presented with several time-compressed sentences, young adults' performance improves with practice. Such adaptation has not been studied in older adults. To study age-related changes in perceptual learning, the authors tested young and older adults' ability to adapt to degraded speech. First, the authors showed that older adults, when equated for starting accuracy with young adults, adapted at a rate and magnitude comparable to young adults. However, unlike young adults, older adults failed to transfer this learning to a different speech rate and did not show additional benefit when practice exceeded 20 sentences. Listeners did not adapt to speech degraded by noise, indicating that adaptation to time-compressed speech was not attributable to task familiarity. Finally, both young and older adults adapted to spectrally shifted noise-vocoded speech. The authors conclude that initial perceptual learning is comparable in young and older adults but maintenance and transfer of this learning decline with age.

Fast noisy speech: Age differences in processing rapid speech with background noise.

In order to investigate the effects of age on the ability to process speech under conditions of background noise, younger and older adults listened to and reported time-compressed spoken sentences presented with varying levels of background babble. Although the two age groups did not differ significantly in terms of either pure tone averages or in the ability to accurately report the sentences when they were presented in quiet, the older participants showed less tolerance for background noise than younger adults. This age difference in performance was further magnified by increased speech rates, suggesting that both age-related slowing of processing and reduced inhibition of distracting sounds may produce age deficits in speech processing.