ERP mismatch response to phonological and temporal regularities in speech

Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system's sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.Maastricht University (Grant to BMJ to support women in higher academic positions) and Netherlands Organization for Scientific Research (NWO) 452-16-004info:eu-repo/semantics/publishedVersio

A neural signature of regularity in sound is reduced in older adults

Sensitivity to repetitions in sound amplitude and frequency is crucial for sound perception. As with other aspects of sound processing, sensitivity to such patterns may change with age, and may help explain some age-related changes in hearing such as segregating speech from background sound. We recorded magnetoencephalography to characterize differences in the processing of sound patterns between younger and older adults. We presented tone sequences that either contained a pattern (made of a repeated set of tones) or did not contain a pattern. We show that auditory cortex in older, compared to younger, adults is hyperresponsive to sound onsets, but that sustained neural activity in auditory cortex, indexing the processing of a sound pattern, is reduced. Hence, the sensitivity of neural populations in auditory cortex fundamentally differs between younger and older individuals, overresponding to sound onsets, while underresponding to patterns in sounds. This may help to explain some age-related changes in hearing such as increased sensitivity to distracting sounds and difficulties tracking speech in the presence of other sound

Acceptable Noise Levels and Electrophysiological Measures in Listeners with Hearing Impairment

Acceptable noise level (ANL) is a measure of a listener’s acceptance of background noise when listening to speech. A consistent finding in research on ANL is large intersubject variability in the acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, type of background noise, speech perception in noise performance, cochlear responses, or efferent activity of the medial olivocochlear bundle pathways. Moreover, across ANL studies, young and elderly individuals with both hearing impairment and normal-hearing sensitivity display equivalent means and ranges for ANLs, indicating that acceptance of background noise may be an inherent characteristic of the individual that does not change with age, or the development of hearing loss. In the present study, auditory evoked potentials and encephalography (EEG) were examined in 40 adults with mild-to-moderately-severe sensorineural hearing impairment with low, mid-range, and high ANLs to determine whether or not differences in judgments of background noise are related to differences measured in aggregate physiological responses from the auditory nervous system. Group differences in the auditory brainstem response, auditory middle latency, cortical, auditory late latency, and EEG responses indicate that differences in more central regions of the nervous system contribute to the variability in the willingness of a listener with hearing impairment to accept background noise when listening to speech

Cross-language speech perception in context : advantages for recent language learners and variation across language-specific acoustic cues

This dissertation explores the relationship between language experience and sensitivity to language-specific segmental cues by comparing cross-language speech perception in monolingual English listeners and Spanish-English bilinguals. The three studies in this project use a novel language categorization task to test language-segment associations in listeners’ first and second languages. Listener sensitivity is compared at two stages of development and across a variety of language backgrounds. These studies provide a more complete analysis of listeners’ language-specific phonological categories than offered in previous work by using word-length stimuli to evaluate segments in phonological contexts and by testing speech perception in listeners’ first language as well as their second language. The inclusion of bilingual children also allows connections to be drawn between previous work on infants’ perception of segments and the sensitivities of bilingual adults. In three experiments, participants categorized nonce words containing different classes of English- and Spanish-specific sounds as sounding more English-like or Spanish-like; target segments were either a phonemic cue, a cue for which there is no analogous sound in the other language, or a phonetic cue, a cue for which English and Spanish share the category but for which each language varies in its phonetic implementation. The results reveal a largely consistent categorization pattern across target segments. Listeners from all groups succeeded and struggled with the same subsets of language-specific segments. The same pattern of results held in a task where more time was given to make categorization decisions. Interestingly, for some segments the late bilinguals were significantly more accurate than monolingual and early bilingual listeners, and this was the case for the English phonemic cues. There were few differences in the sensitivity of monolinguals and early bilinguals to language-specific cues, suggesting that the early bilinguals’ exposure to Spanish did not fundamentally change their representations of English phonology, but neither did their proficiency in Spanish give them an advantage over monolinguals. The comparison of adult listeners with children indicates that the Spanish-speaking children who grow to be early bilingual adults categorize segments more accurately than monolinguals – a pattern that is neutralized in the adult results. These findings suggest that variation in listener sensitivity to language-specific cues is largely driven by inherent differences in the salience of the segments themselves. Listener language experience modulates the salience of some of these sounds, and these differences in cross-language speech perception may reflect how recently a language was learned and under what circumstances.Linguistic

Objective Measures of Electrode Discrimination With Electrically Evoked Auditory Change Complex and Speech-Perception Abilities in Children With Auditory Neuropathy Spectrum Disorder

This study aimed to 1) determine the sensitivity of the electrically evoked auditory change complex (eACC) to changes in stimulating electrode position; and 2) investigate the association between results of eACC measures and behavioral electrode discrimination and their association with speech-perception performance in pediatric cochlear implant (CI) users who have auditory neuropathy spectrum disorder (ANSD)

An Investigation of the Effects of Categorization and Discrimination Training on Auditory Perceptual Space

Psychophysical phenomena such as categorical perception and the perceptual magnet effect indicate that our auditory perceptual spaces are warped for some stimuli. This paper investigates the effects of two different kinds of training on auditory perceptual space. It is first shown that categorization training, in which subjects learn to identify stimuli within a particular frequency range as members of the same category, can lead to a decrease in sensitivity to stimuli in that category. This phenomenon is an example of acquired similarity and apparently has not been previously demonstrated for a category-relevant dimension. Discrimination training with the same set of stimuli was shown to have the opposite effect: subjects became more sensitive to differences in the stimuli presented during training. Further experiments investigated some of the conditions that are necessary to generate the acquired similarity found in the first experiment. The results of these experiments are used to evaluate two neural network models of the perceptual magnet effect. These models, in combination with our experimental results, are used to generate an experimentally testable hypothesis concerning changes in the brain's auditory maps under different training conditions.Alfred P. Sloan Foundation and the National institutes of Deafness and other Communication Disorders (R29 02852); Air Force Office of Scientific Research (F49620-98-1-0108

Sensitivity to speech rhythm explains individual differences in reading ability independently of phonological awareness

This study considered whether sensitivity to speech rhythm can predict concurrent variance in reading attainment after individual differences in age, vocabulary and phonological awareness have been controlled. Five to six-year-old English-speaking children completed a battery of phonological processing assessments and reading assessments, along with a simple word stress manipulation task. The results showed that performance on the stress manipulation measure predicted a significant amount of variance in reading attainment after age, vocabulary, and phonological processing had been taken into account. These results suggest that stress sensitivity is an important, yet neglected aspect of English-speaking children?s phonological representations, which needs to be incorporated into theoretical accounts of reading development

The development of the Arabic lexical neighbourhood test

Speech perception is a primary outcome measure in children using cochlear implants (CI). Saudi Arabia has a high prevalence of hearing loss, however, there are no appropriate measures to assess communication skills in these children post cochlear implantation. This thesis describes the development and application of an Arabic version of the Lexical Neighbourhood Test (Kirk, Pisoni, & Osberger, 1995) for children using CIs in Saudi Arabia. Study 1 consisted of language sampling and developing the Arabic Lexical Neighbourhood Test (ALNT) word lists. Study 2 examined performance of normal hearing (NH) children on the ALNT in two conditions: in noise and in quiet via vocoded speech simulating a CI. Study 3 investigated the performance of CI children on the ALNT in quiet over time, with 3 measurements made over a period of approximately 18 months. In general, results indicated that the ALNT was a reliable speech perception test. Both CI and NH children consistently scored higher on the easy words than the hard words which is consistent with the effects of the lexical factors of word frequency and neighbourhood density on speech perception. Another factor that was also explored was whether repeated administration of test items affected performance. In NH children, when time intervals between first and second administration was 2-4 weeks, repetition effects were evident. In CI children however, when the test intervals between repeated administrations was 6-9 months apart, repetition effects were not evident. This demonstrates that the ALNT can be used repeatedly without affecting speech perception performance. Finally, the sensitivity of the ALNT to change in performance over time was compared to a nonsense CV test that was also administered to CI children over three sessions. The CV test was found to be more sensitive to change over time than the ALNT

The relationship of phonological ability, speech perception, and auditory perception in adults with dyslexia

This study investigated whether auditory, speech perception and phonological skills are tightly interrelated or independently contributing to reading. We assessed each of these three skills in 36 adults with a past diagnosis of dyslexia and 54 matched normal reading adults. Phonological skills were tested by the typical threefold tasks, i.e. rapid automatic naming, verbal short term memory and phonological awareness. Dynamic auditory processing skills were assessed by means of a frequency modulation (FM) and an amplitude rise time (RT); an intensity discrimination task (ID) was included as a non-dynamic control task. Speech perception was assessed by means of sentences and words in noise tasks. Group analysis revealed significant group differences in auditory tasks (i.e. RT and ID) and in phonological processing measures, yet no differences were found for speech perception. In addition, performance on RT discrimination correlated with reading but this relation was mediated by phonological processing and not by speech in noise. Finally, inspection of the individual scores revealed that the dyslexic readers showed an increased proportion of deviant subjects on the slow-dynamic auditory and phonological tasks, yet each individual dyslexic reader does not display a clear pattern of deficiencies across the levels of processing skills. Although our results support phonological and slow-rate dynamic auditory deficits which relate to literacy, they suggest that at the individual level, problems in reading and writing cannot be explained by the cascading auditory theory. Instead, dyslexic adults seem to vary considerably in the extent to which each of the auditory and phonological factors are expressed and interact with environmental and higher-order cognitive influences

Asymmetric discrimination of non-speech tonal analogues of vowels

Published in final edited form as: J Exp Psychol Hum Percept Perform. 2019 February ; 45(2): 285–300. doi:10.1037/xhp0000603.Directional asymmetries reveal a universal bias in vowel perception favoring extreme vocalic articulations, which lead to acoustic vowel signals with dynamic formant trajectories and well-defined spectral prominences due to the convergence of adjacent formants. The present experiments investigated whether this bias reflects speech-specific processes or general properties of spectral processing in the auditory system. Toward this end, we examined whether analogous asymmetries in perception arise with non-speech tonal analogues that approximate some of the dynamic and static spectral characteristics of naturally-produced /u/ vowels executed with more versus less extreme lip gestures. We found a qualitatively similar but weaker directional effect with two-component tones varying in both the dynamic changes and proximity of their spectral energies. In subsequent experiments, we pinned down the phenomenon using tones that varied in one or both of these two acoustic characteristics. We found comparable asymmetries with tones that differed exclusively in their spectral dynamics, and no asymmetries with tones that differed exclusively in their spectral proximity or both spectral features. We interpret these findings as evidence that dynamic spectral changes are a critical cue for eliciting asymmetries in non-speech tone perception, but that the potential contribution of general auditory processes to asymmetries in vowel perception is limited.Accepted manuscrip