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Many children have difficulties understanding speech. Reliable tools are needed to identify them in order to provide appropriate interventions. At present, there are relatively few assessments that test for subtle impairments in speech... more
Many children have difficulties understanding speech. Reliable tools are needed to identify them in order to provide appropriate interventions. At present, there are relatively few assessments that test for subtle impairments in speech perception that have normative data from UK children. Here we present a new test, which evaluates children’s ability to identify target words in background noise by choosing between minimal pair alternatives that differ by a single articulatory phonetic feature. This new test of single word perception is (1) tailored to testing young children, (2) has minimal memory demands, (3) adapts to the child’s ability and (4) does not require reading or verbal output. Although designed for young children, it is also readily applicable in adults. Here, we show that speech in noise abilities in this particular task develop rapidly through childhood until they reach maturity at around ten years of age. We make this test freely available, with normative data for li...
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Research Interests: Psychology and Audiology
Research Interests: Computer Science and RF
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The purpose of the study was to assess the ability of children with developmental language learning impairments (LLIs) to use visual speech cues from the talking face. In this cross-sectional study, 41 typically developing children (mean... more
The purpose of the study was to assess the ability of children with developmental language learning impairments (LLIs) to use visual speech cues from the talking face. In this cross-sectional study, 41 typically developing children (mean age: 8 years 0 months, range: 4 years 5 months to 11 years 10 months) and 27 children with diagnosed LLI (mean age: 8 years 10 months, range: 5 years 2 months to 11 years 6 months) completed a silent speechreading task and a speech-in-noise task with and without visual support from the talking face. The speech-in-noise task involved the identification of a target word in a carrier sentence with a single competing speaker as a masker. Children in the LLI group showed a deficit in speechreading when compared with their typically developing peers. Beyond the single-word level, this deficit became more apparent in older children. On the speech-in-noise task, a substantial benefit of visual cues was found regardless of age or group membership, although the LLI group showed an overall developmental delay in speech perception. Although children with LLI were less accurate than their peers on the speechreading and speech-in noise-tasks, both groups were able to make equivalent use of visual cues to boost performance accuracy when listening in noise.
Research Interests: Psychology, Cognitive Science, Perception, Audiology, Language Development, and 15 moreLinguistics, Language Therapy, Medicine, Humans, Child, Female, Male, Active Listening, Clinical Sciences, Cross Sectional Studies, Acoustic Stimulation, Child preschool, photic stimulation, Language Development Disorders, and Language tests
PURPOSE Many children have difficulties understanding speech. At present, there are few assessments that test for subtle impairments in speech perception with normative data from U.K. children. We present a new test that evaluates... more
PURPOSE Many children have difficulties understanding speech. At present, there are few assessments that test for subtle impairments in speech perception with normative data from U.K. children. We present a new test that evaluates children's ability to identify target words in background noise by choosing between minimal pair alternatives that differ by a single articulatory phonetic feature. This task (a) is tailored to testing young children, but also readily applicable to adults; (b) has minimal memory demands; (c) adapts to the child's ability; and (d) does not require reading or verbal output. METHOD We tested 155 children and young adults aged from 5 to 25 years on this new test of single word perception. RESULTS Speech-in-noise abilities in this particular task develop rapidly through childhood until they reach maturity at around 9 years of age. CONCLUSIONS We make this test freely available and provide associated normative data. We hope that it will be useful to rese...
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When attempting to maintain conversations in noisy communicative settings, talkers typically modify their speech to make themselves understood by the listener. In this study, we investigated the impact of background interference type and... more
When attempting to maintain conversations in noisy communicative settings, talkers typically modify their speech to make themselves understood by the listener. In this study, we investigated the impact of background interference type and talker age on speech adaptations, vocal effort and communicative success. We measured speech acoustics (articulation rate, mid-frequency energy, fundamental frequency), vocal effort (correlation between mid-frequency energy and fundamental frequency) and task completion time in 114 participants aged 8–80 years carrying out an interactive problem-solving task in good and noisy listening conditions (quiet, non-speech noise, background speech). We found greater changes in fundamental frequency and mid-frequency energy in non-speech noise than in background speech and similar reductions in articulation rate in both. However, older participants (50+ years) increased vocal effort in both background interference types, whereas younger children (less than 1...
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Auditory deprivation in the form of deafness during development leads to lasting changes in central auditory system function. However, less is known about the effects of mild-to-moderate sensorineural hearing loss (MMHL) during... more
Auditory deprivation in the form of deafness during development leads to lasting changes in central auditory system function. However, less is known about the effects of mild-to-moderate sensorineural hearing loss (MMHL) during development. Here, we used a longitudinal design to examine late auditory evoked responses and mismatch responses to nonspeech and speech sounds for children with MMHL. At Time 1, younger children with MMHL (8–12 years; n = 23) showed age-appropriate mismatch negativities (MMNs) to sounds, but older children (12–16 years; n = 23) did not. Six years later, we re-tested a subset of the younger (now older) children with MMHL (n = 13). Children who had shown significant MMNs at Time 1 showed MMNs that were reduced and, for nonspeech, absent at Time 2. Our findings demonstrate that even a mild-to-moderate hearing loss during early-to-mid childhood can lead to changes in the neural processing of sounds in late childhood/adolescence.
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Research Interests: Psychology, Cognitive Science, Speech perception, Magnetic Resonance Imaging, Adolescent, and 15 moreMedicine, Multivariate Analysis, Brain Mapping, Temporal Lobe, Humans, Cerebral Cortex, Functional Magnetic Resonance Imaging, Female, Male, Speech Intelligibility, Adult, Auditory Threshold, Neural pathways, Auditory Cortex, and Neurosciences
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It is still unclear whether the gradual improvement in amplitude-modulation (AM) sensitivity typically found in children up to 10 years of age reflects an improvement in "processing efficiency" (the central ability to use... more
It is still unclear whether the gradual improvement in amplitude-modulation (AM) sensitivity typically found in children up to 10 years of age reflects an improvement in "processing efficiency" (the central ability to use information extracted by sensory mechanisms). This hypothesis was tested by evaluating temporal integration for AM, a capacity relying on memory and decision factors. This was achieved by measuring the effect of increasing the number of AM cycles (2 vs 8) on AM-detection thresholds for three groups of children aged from 5 to 11 years and a group of young adults. AM-detection thresholds were measured using a forced-choice procedure and sinusoidal AM (4 or 32 Hz rate) applied to a 1024-Hz pure-tone carrier. All age groups demonstrated temporal integration for AM at both rates; that is, significant improvements in AM sensitivity with a higher number of AM cycles. However, an effect of age is observed as both 5-6 year olds and adults exhibited more temporal integration compared to 7-8 and 10-11 year olds at both rates. This difference is due to: (i) the 5-6 year olds displaying the worst thresholds with 2 AM cycles, but similar thresholds with 8 cycles compared to the 7-8 and 10-11 year olds, and, (ii) adults showing the best thresholds with 8 AM cycles but similar thresholds with 2 cycles compared to the 7-8 and 10-11 year olds. Computational modelling indicated that higher levels of internal noise combined with poorer short-term memory capacities in children accounted for the developmental trends. Improvement in processing efficiency may therefore account for the development of AM detection in childhood. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
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The ability to detect amplitude modulation (AM) is essential to distinguish the spectro-temporal features of speech from those of a competing masker. Previous work shows that AM sensitivity improves until 10 years of age. This may relate... more
The ability to detect amplitude modulation (AM) is essential to distinguish the spectro-temporal features of speech from those of a competing masker. Previous work shows that AM sensitivity improves until 10 years of age. This may relate to the development of sensory factors (tuning of AM filters, susceptibility to AM masking) or to changes in processing efficiency (reduction in internal noise, optimization of decision strategies). To disentangle these hypotheses, three groups of children (5–11 years) and one of young adults completed psychophysical tasks measuring thresholds for detecting sinusoidal AM (with a rate of 4, 8, or 32 Hz) applied to carriers whose inherent modulations exerted different amounts of AM masking. Results showed that between 5 and 11 years, AM detection thresholds improved and that susceptibility to AM masking slightly increased. However, the effects of AM rate and carrier were not associated with age, suggesting that sensory factors are mature by 5 years. Su...
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Psychophysical thresholds were measured for 8-16 year-old children with mild-to-moderate sensorineural hearing loss (MMHL; N = 46) on a battery of auditory processing tasks that included measures designed to be predominantly reliant upon... more
Psychophysical thresholds were measured for 8-16 year-old children with mild-to-moderate sensorineural hearing loss (MMHL; N = 46) on a battery of auditory processing tasks that included measures designed to be predominantly reliant upon frequency selectivity, and sensitivity to temporal fine structure (TFS) or envelope cues. Children with MMHL who wore hearing aids were tested in both unaided and aided conditions, and all were compared to a group of normally hearing (NH) age-matched controls. Children with MMHL performed more poorly than NH controls on tasks considered to be dependent upon frequency selectivity, sensitivity to TFS, and speech discrimination (/bɑ/-/dɑ/), but not on tasks measuring sensitivity to envelope cues. Auditory processing deficits remained regardless of age, were observed in both unaided and aided conditions, and could not be attributed to differences in nonverbal IQ or attention between groups. However, better auditory processing for children with MMHL was ...
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Objectives: This study aimed to evaluate the informational component of speech-on-speech masking. Speech perception in the presence of a competing talker involves not only informational masking (IM) but also a number of masking processes... more
Objectives: This study aimed to evaluate the informational component of speech-on-speech masking. Speech perception in the presence of a competing talker involves not only informational masking (IM) but also a number of masking processes involving interaction of masker and target energy in the auditory periphery. Such peripherally generated masking can be eliminated by presenting the target and masker in opposite ears (dichotically). However, this also reduces IM by providing listeners with lateralization cues that support spatial release from masking (SRM). In tonal sequences, IM can be isolated by rapidly switching the lateralization of dichotic target and masker streams across the ears, presumably producing ambiguous spatial percepts that interfere with SRM. However, it is not clear whether this technique works with speech materials. Design: Speech reception thresholds (SRTs) were measured in 17 young normal-hearing adults for sentences produced by a female talker in the presence...
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An interactive method for training speech perception in noise was assessed with adult cochlear implant users. The method employed recordings of connected narratives divided into phrases of 4 to 10 words, presented in babble. After each... more
An interactive method for training speech perception in noise was assessed with adult cochlear implant users. The method employed recordings of connected narratives divided into phrases of 4 to 10 words, presented in babble. After each phrase, the listener identified key words from the phrase from among similar sounding foil words. Nine postlingually deafened adult cochlear implant users carried out 12 hr of training over a 4-week period. Training was carried out at home on tablet computers. The primary outcome measure was sentence recognition in babble. Vowel and consonant identification in speech-shaped noise were also assessed, along with digit span in noise, intended as a measure of some important underlying cognitive abilities. Talkers for speech tests were different from those used in training. To control for procedural learning, the test battery was administered repeatedly prior to training. Performance was assessed immediately after training and again after a further 4 weeks...
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When assessing the intelligibility of speech embedded in background noise, maskers with a harmonic spectral structure have been found to be much less detrimental to performance than noise-based interferers. While spectral “glimpsing” in... more
When assessing the intelligibility of speech embedded in background noise, maskers with a harmonic spectral structure have been found to be much less detrimental to performance than noise-based interferers. While spectral “glimpsing” in between the resolved masker harmonics and reduced envelope modulations of harmonic maskers have been shown to contribute, this effect has primarily been attributed to the proposed ability of the auditory system to cancel harmonic maskers from the signal mixture. Here, speech intelligibility in the presence of harmonic and inharmonic maskers with similar spectral glimpsing opportunities and envelope modulation spectra was assessed to test the theory of harmonic cancellation. Speech reception thresholds obtained from normal-hearing listeners revealed no effect of masker harmonicity, neither for maskers with static nor dynamic pitch contours. The results show that harmonicity, or time-domain periodicity, as such, does not aid the segregation of speech a...
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Page 1. The Journal of Laryngology and Otology September 1982. Vol. 96. pp. 811-816 Electrical auditory stimulation in the management of profound hearing loss An up-dated report to the Department of Health and Social Security ...
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For small numbers of channels, tone vocoders using low envelope cutoff frequencies are less intelligible than noise vocoders, even though the noise carriers introduce random fluctuations into the crucial envelope information. Here it is... more
For small numbers of channels, tone vocoders using low envelope cutoff frequencies are less intelligible than noise vocoders, even though the noise carriers introduce random fluctuations into the crucial envelope information. Here it is shown that using tone carriers with a denser spectrum improves performance considerably over typical tone vocoders, at least equaling, and often surpassing, the performance possible with noise vocoders. In short, the spectral sparseness of tone vocoded sounds for low channel numbers, separate from the degradations introduced by using only a small number of channels, is an important limitation on the intelligibility of tone-vocoded speech.
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This study investigated whether children with dyslexia (DYS) are more affected by talker and prosodic variability when perceiving speech in noise than age‐matched average readers (ARs). 34 DYS and 25 AR children carried out... more
This study investigated whether children with dyslexia (DYS) are more affected by talker and prosodic variability when perceiving speech in noise than age‐matched average readers (ARs). 34 DYS and 25 AR children carried out syllable‐initial consonant perception tests, ...
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Purpose In this study, the authors aimed to determine whether children with dyslexia (hereafter referred to as “DYS children”) are more affected than children with average reading ability (hereafter referred to as “AR children”) by talker... more
Purpose In this study, the authors aimed to determine whether children with dyslexia (hereafter referred to as “DYS children”) are more affected than children with average reading ability (hereafter referred to as “AR children”) by talker and intonation variability when perceiving speech in noise. Method Thirty-four DYS and 25 AR children were tested on their perception of consonants in naturally produced CV tokens in multitalker babble. Twelve CVs were presented for identification in four conditions varying in the degree of talker and intonation variability. Consonant place (/bi/-/di/) and voicing (/bi/-/pi/) discrimination were investigated with the same conditions. Results DYS children made slightly more identification errors than AR children but only for conditions with variable intonation. Errors were more frequent for a subset of consonants, generally weakly encoded for AR children, for tokens with intonation patterns (steady and rise-fall) that occur infrequently in connected...
Research Interests: Psychology, Cognitive Science, Phonetics, Speech perception, Linguistics, and 15 moreAdolescent, Dyslexia, Medicine, Speech, Humans, Child, Noise, Female, Male, Clinical Sciences, Short Term Memory, Intelligence tests, Predictive value of tests, Contingent Negative Variation, and Acoustic Stimulation
Purpose The claim that speech perception abilities are impaired in dyslexia was investigated in a group of 62 children with dyslexia and 51 average readers matched in age. Method To test whether there was robust evidence of speech... more
Purpose The claim that speech perception abilities are impaired in dyslexia was investigated in a group of 62 children with dyslexia and 51 average readers matched in age. Method To test whether there was robust evidence of speech perception deficits in children with dyslexia, speech perception in noise and quiet was measured using 8 different tasks involving the identification and discrimination of a complex and highly natural synthetic “bee”–“pea” contrast (copy synthesized from natural models) and the perception of naturally produced words. Results Children with dyslexia, on average, performed more poorly than did average readers in the synthetic syllables identification task in quiet and in across-category discrimination (but not when tested using an adaptive procedure). They did not differ from average readers on 2 tasks of word recognition in noise or identification of synthetic syllables in noise. For all tasks, a majority of individual children with dyslexia performed within...
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Receptive language impairments in school-age children have a poor prognosis, yet there is a dearth of research on effective interventions. Children's responses to a computerized grammatical training program were evaluated... more
Receptive language impairments in school-age children have a poor prognosis, yet there is a dearth of research on effective interventions. Children's responses to a computerized grammatical training program were evaluated to consider whether repeated responding to spoken sentences with variable semantic content and the same syntactic structure would lead to consistent and fluent comprehension. Children with receptive language impairments aged from 8 to 13 years were randomly assigned to three groups: Group S (n = 12) responded to reversible sentences in a computerized game, using speech stimuli with pauses before critical phrases. Group M (n = 12) had the same stimuli acoustically modified to lengthen and amplify dynamic portions of the signal. Group U (n = 9) was an untrained control group. On average, children in groups S and M completed over 1000 training trials, focusing on training comprehension of reversible sentences. Although responses speeded up over the course of training, and most children performed well above chance, accuracy typically remained below 95% correct for constructions such as above/below and reversible active/passive. Trained groups did not differ from untrained children on language or auditory outcomes. There was no evidence that acoustically modified speech input enhanced comprehension. Rote training of comprehension of reversible sentences does not seem to be an effective approach to remediating such problems. For most children, the pattern of performance suggested that the problem was not a lack of syntactic knowledge, bur rather limited processing capacity that led to failures of on-line computation of meaning.
Research Interests: Psychology, Cognitive Science, Auditory Perception, Cognition, Speech Acoustics, and 15 moreLinguistics, Adolescent, Specific Language Impairment, Language Therapy, Language Impairment, Medicine, Speech, Humans, Child, Discrimination Learning, Comprehension, Reaction Time, Clinical Sciences, Control Group, and Language Development Disorders
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Twenty 9- to 12-year-olds with specific language impairment (SLI) were compared with 18 age-matched controls on auditory discrimination tasks, using a three-interval, two-alternative forced-choice format. The first task used minimal word... more
Twenty 9- to 12-year-olds with specific language impairment (SLI) were compared with 18 age-matched controls on auditory discrimination tasks, using a three-interval, two-alternative forced-choice format. The first task used minimal word pairs in silence and in noise. Nonspeech tasks involved discriminating direction of frequency glides and had two versions: (a) the glide moved from 500 to 1500 Hz, and duration was adaptively decreased; (b) all glides lasted 250 ms, and the frequency range was adaptively modified until a threshold was reached. Control and SLI groups did not differ on the glide tasks. Around half the children in both groups accurately discriminated 20 ms glides. There was a small but significant group difference on the speech-in-noise task, and scores were weakly related to literacy level. Perception of brief, transient, nonspeech stimuli is not abnormal in the majority of school-aged children with SLI.
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Research Interests: Psychology, Perception, Signal Processing, Psychoacoustics, Neurophysiology, and 15 morePositron Emission Tomography, Medicine, Multidisciplinary, Humans, Noise, Female, Male, Speech Intelligibility, Intelligibility, Middle Aged, Adult, Background Noise, Auditory Cortex, Cerebro, and Acoustic Stimulation
Purpose We investigated claims that specific language impairment (SLI) typically arises from nonspeech auditory deficits by measuring tone-in-noise thresholds in a relatively homogeneous SLI subgroup exhibiting a primary deficit... more
Purpose We investigated claims that specific language impairment (SLI) typically arises from nonspeech auditory deficits by measuring tone-in-noise thresholds in a relatively homogeneous SLI subgroup exhibiting a primary deficit restricted to grammar (Grammatical[G]-SLI). Method Fourteen children (mostly teenagers) with G-SLI were compared to age-, vocabulary-, and grammar-matched control children on their abilities to detect a brief tone in quiet and in the presence of a masking noise. The tone occurred either simultaneously with the noise or just preceding it (backward masking). Maskers with and without a spectral notch allowed estimates of frequency selectivity. Results Group thresholds for the G-SLI children were never worse than those obtained for younger controls but were higher in both backward and simultaneous masking than in age-matched controls. However, more than half of the G-SLI group (8/14) were within age-appropriate limits for all thresholds. Frequency selectivity in...
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Purpose The goal of this study was to examine language development and factors related to language impairments in children with mild to moderate sensorineural hearing loss (MMHL). Method Ninety children, aged 8–16 years (46 children with... more
Purpose The goal of this study was to examine language development and factors related to language impairments in children with mild to moderate sensorineural hearing loss (MMHL). Method Ninety children, aged 8–16 years (46 children with MMHL; 44 aged-matched controls), were administered a battery of standardized language assessments, including measures of phonological processing, receptive and expressive vocabulary and grammar, word and nonword reading, and parental report of communication skills. Group differences were examined after controlling for nonverbal ability. Results Children with MMHL performed as well as controls on receptive vocabulary and word and nonword reading. They also performed within normal limits, albeit significantly worse than controls, on expressive vocabulary, and on receptive and expressive grammar, and worse than both controls and standardized norms on phonological processing and parental report of communication skills. However, there was considerable va...
Research Interests: Cognitive Science, Psychometrics, Audiology, Language Development, Linguistics, and 12 moreAdolescent, Humans, Child, Hearing Loss, Risk factors, Clinical Sciences, Educational Status, Risk Factors, Surveys and Questionnaires, Language Development Disorders, Speech Language and Hearing Sciences, and Language tests
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Purpose In this study, the authors explored phonological processing in connected speech in children with hearing loss. Specifically, the authors investigated these children's sensitivity to English place assimilation, by which... more
Purpose In this study, the authors explored phonological processing in connected speech in children with hearing loss. Specifically, the authors investigated these children's sensitivity to English place assimilation, by which alveolar consonants like t and n can adapt to following sounds (e.g., the word te n can be realized as te m in the phrase te n p ounds ). Method Twenty-seven 4- to 8-year-old children with moderate to profound hearing impairments, using hearing aids ( n = 10) or cochlear implants ( n = 17), and 19 children with normal hearing participated. They were asked to choose between pictures of familiar (e.g., pen) and unfamiliar objects (e.g., astrolabe) after hearing t - and n -final words in sentences. Standard pronunciations ( Can you find the pe n d ear ?) and assimilated forms in correct (… pe m p lease? ) and incorrect contexts (… pe m dear? ) were presented. Results As expected, the children with normal hearing chose the familiar object more often for standa...
Research Interests: Cognitive Science, Phonology, Phonetics, Speech perception, English, and 15 moreLinguistics, Language, Adolescent, Speech, Humans, Child, Hearing aids, Female, Male, Cochlear Implants, Assimilation, Clinical Sciences, Cochlear Implantation, Severity of Illness Index, and Speech Language and Hearing Sciences
The question of hemispheric lateralization of neural processes is one that is pertinent to a range of subdisciplines of cognitive neuroscience. Language is often assumed to be left-lateralized in the human brain, but there has been a long... more
The question of hemispheric lateralization of neural processes is one that is pertinent to a range of subdisciplines of cognitive neuroscience. Language is often assumed to be left-lateralized in the human brain, but there has been a long running debate about the underlying reasons for this. We addressed this problem with fMRI by identifying the neural responses to amplitude and spectral modulations in speech and how these interact with speech intelligibility to test previous claims for hemispheric asymmetries in acoustic and linguistic processes in speech perception. We used both univariate and multivariate analyses of the data, which enabled us to both identify the networks involved in processing these acoustic and linguistic factors and to test the significance of any apparent hemispheric asymmetries. We demonstrate bilateral activation of superior temporal cortex in response to speech-derived acoustic modulations in the absence of intelligibility. However, in a contrast of ampli...
Research Interests: Cognitive Science, Computer Science, Magnetic Resonance Imaging, Linguistics, Cognitive Neuroscience, and 15 moreMedicine, Cognitive, Brain Mapping, Brain, Humans, Female, Male, Hemispheric Asymmetry, Human Brain, Adult, Analysis of Variance, Left Hemisphere, Functional Laterality, Acoustic Stimulation, and multivariate analyses
It has been previously demonstrated that extensive activation in the dorsolateral temporal lobes associated with masking a speech target with a speech masker, consistent with the hypothesis that competition for central auditory processes... more
It has been previously demonstrated that extensive activation in the dorsolateral temporal lobes associated with masking a speech target with a speech masker, consistent with the hypothesis that competition for central auditory processes is an important factor in informational masking. Here, masking from speech and two additional maskers derived from the original speech were investigated. One of these is spectrally rotated speech, which is unintelligible and has a similar (inverted) spectrotemporal profile to speech. The authors also controlled for the possibility of "glimpsing" of the target signal during modulated masking sounds by using speech-modulated noise as a masker in a baseline condition. Functional imaging results reveal that masking speech with speech leads to bilateral superior temporal gyrus (STG) activation relative to a speech-in-noise baseline, while masking speech with spectrally rotated speech leads solely to right STG activation relative to the baseline...
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Research Interests: Speech perception, Magnetic Resonance Imaging, Speech, Brain Mapping, Temporal Lobe, and 10 moreBrain, Humans, PET imaging, Speech Intelligibility, Single Photon Emission Computed Tomography, Auditory Cortex, Functional Laterality, Acoustic Stimulation, Psychology and Cognitive Sciences, and Medical and Health Sciences
Purpose This study investigated whether adults with dyslexia show evidence of a consistent speech perception deficit by testing phoneme categorization and word perception in noise. Method Seventeen adults with dyslexia and 20 average... more
Purpose This study investigated whether adults with dyslexia show evidence of a consistent speech perception deficit by testing phoneme categorization and word perception in noise. Method Seventeen adults with dyslexia and 20 average readers underwent a test battery including standardized reading, language and phonological awareness tests, and tests of speech perception. Categorization of a pea/bee voicing contrast was evaluated using adaptive identification and discrimination tasks, presented in quiet and in noise, and a fixed-step discrimination task. Two further tests of word perception in noise were presented. Results There were no significant group differences for categorization in quiet or noise, across- and within-category discrimination as measured adaptively, or word perception, but average readers showed better across- and within-category discrimination in the fixed-step discrimination task. Individuals did not show consistent poor performance across related tasks. Conclus...
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Older adults, even those without hearing impairment, often experience increased difficulties understanding speech in the presence of background noise. This study examined the role of age-related declines in subcortical auditory processing... more
Older adults, even those without hearing impairment, often experience increased difficulties understanding speech in the presence of background noise. This study examined the role of age-related declines in subcortical auditory processing in the perception of speech in different types of background noise. Participants included normal-hearing young (19 - 29 years) and older (60 - 72 years) adults. Normal hearing was defined as pure-tone thresholds of 25 dB HL or better at octave frequencies from 0.25 to 4 kHz in both ears and at 6 kHz in at least one ear. Speech reception thresholds (SRTs) to sentences were measured in steady-state (SS) and 10-Hz amplitude-modulated (AM) speech-shaped noise, as well as two-talker babble. In addition, click-evoked auditory brainstem responses (ABRs) and envelope following responses (EFRs) in response to the vowel /ɑ/ in quiet, SS, and AM noise were measured. Of primary interest was the relationship between the SRTs and EFRs. SRTs were significantly hi...
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This study examined the effects of sentence predictability and masker modulation type on the fluctuating masker benefit (FMB), the improvement in speech reception thresholds resulting from fluctuations imposed on a steady-state masker.... more
This study examined the effects of sentence predictability and masker modulation type on the fluctuating masker benefit (FMB), the improvement in speech reception thresholds resulting from fluctuations imposed on a steady-state masker. Square-wave modulations resulted in a larger FMB than sinusoidal ones. FMBs were also larger for high compared to low-predictability sentences, indicating that high sentence predictability increases the benefits from glimpses of the target speech in the dips of the fluctuating masker. In addition, sentence predictability appears to have a greater effect on sentence intelligibility when the masker is fluctuating than when it is steady-state.