International journal of speech-language pathology, 2012
This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old f... more This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old female following total glossectomy. Speech samples were collected on three occasions within the first 3 months following glossectomy. Vowel articulation was examined acoustically as a function of vowel space and the Euclidean distance separating corner vowels. Perceptual analyses involved presentation of the participant's CV productions to 30 healthy adult listeners who made forced-choice identifications of consonant type. Acoustic analysis revealed improvements in vowel space area and an increase in the Euclidean distances. The perceptual results revealed a statistically significant deterioration in consonants over the 3-month period with anterior sounds being perceived more correctly than medial and posterior sounds. The current study highlights the variable nature of speech following glossectomy, with greater improvements in vowel articulation compared to consonant articulation du...
The purpose of this study was to determine whether rising-frequency chirps presented via earphone... more The purpose of this study was to determine whether rising-frequency chirps presented via earphones with an extended high-frequency response would optimize the post-auricular muscle response (PAMR). The PAMR was recorded in adults using three different stimuli (a click, a rising-frequency chirp, and a truncated speech stimulus, /t/). Conventional ER-3A insert earphones were compared to ER-2 insert earphones to determine whether the PAMR is enhanced by the ER-2's extended highfrequency response. There were significant stimulus and earphone effects on PAMR amplitudes. The PAMR was largest for the chirp stimulus and the ER-2 earphones. The poorest responses were obtained using the /t/ stimulus and conventional ER-3A earphones. The results support previous ABR studies that have demonstrated a significant advantage of chirps over clicks for evoked response audiometry, and indicate that the PAMR is enhanced by inclusion of additional high-frequency stimulus energy.
We follow up on research demonstrating that aero-tactile in- formation can enhance or interfere w... more We follow up on research demonstrating that aero-tactile in- formation can enhance or interfere with accurate auditory per- ception among uninformed and untrained perceivers [1, 2, 3]. We computationally extract aperiodic information from audi- tory recordings of speech, which represents turbulent air-flow produced from the lips [4, 5]. This extracted signal is used to drive a piezoelectric air-pump producing air-flow to the right temple simultaneous with presentation of auditory recordings. Using forced-choice experiments, we replicate previous results with stops, finding enhanced perception of /pa/ in /pa/ vs. /ba/ pairs, and /ta/ in /ta/ vs. /da/ pairs [1, 6, 2, 3]. We also found enhanced perception of /fa/ in /ba/ vs. /fa/ pairs, and /sha/ in /da/ vs. /sha/ pairs, demonstrating that air flow during fricative pro- duction contacting the skin can also enhance speech perception. The results show that aero-tactile information can be extracted from the audio signal and used to enhance speech perception of a large class of speech sounds found in many languages of the world.
To explore medical oncologists' and audiologists' knowledge and attitudes regarding ototo... more To explore medical oncologists' and audiologists' knowledge and attitudes regarding ototoxicity monitoring, and to gain an understanding of monitoring currently being implemented at District Health Boards (DHBs) nationwide. We also aimed to identify ways in which audiological outcomes for patients receiving potentially ototoxic treatments could be improved, including examining whether the formulation and implementation of a national ototoxicity monitoring guideline is necessary.
This paper evaluated the diagnostic power of electrocochleography (ECochG) in detecting Ménière's... more This paper evaluated the diagnostic power of electrocochleography (ECochG) in detecting Ménière's disease (MD) as compared with two subjective assessment methods, including the clinical guidelines provided by the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing Equilibrium and the Gibson score. A retrospective study of 250 suspected MD cases was conducted. The agreement between the three assessment methods was found to be relatively high, with a total reliability being higher than 70%. Participants who tested "positive" with ECochG exhibited a higher occurrence rate of asymmetric hearing threshold as well as the four MD symptoms, namely, vertigo, hearing loss, tinnitus, and aural fullness. The "positive" ECochG group also showed a high correlation between the ECochG measures in response to stimuli at adjacent frequency ranges, suggesting that the interfrequency ECochG correspondence may be sensitive to the presence of endolymphatic hydrops and thus may serve as a useful diagnostic marker for MD.
This investigation evaluated the familiarisation conditions required to promote subsequent and mo... more This investigation evaluated the familiarisation conditions required to promote subsequent and more long-term improvements in perceptual processing of dysarthric speech and examined the cognitive-perceptual processes that may underlie the experience-evoked learning response. Sixty listeners were randomly allocated to one of three experimental groups and were familiarised under the following conditions: (1) neurologically intact speech (control), (2) dysarthric speech (passive familiarisation), and (3) dysarthric speech coupled with written information (explicit familiarisation). All listeners completed an identical phrase transcription task immediately following familiarisation, and listeners familiarised with dysarthric speech also completed a follow-up phrase transcription task 7 days later. Listener transcripts were analysed for a measure of intelligibility (percent words correct), as well as error patterns at a segmental (percent syllable resemblance) and suprasegmental (lexical boundary errors) level of perceptual processing. The study found that intelligibility scores for listeners familiarised with dysarthric speech were significantly greater than those of the control group, with the greatest and most robust gains afforded by the explicit familiarisation condition. Relative perceptual gains in detecting phonetic and prosodic aspects of the signal varied dependent upon the familiarisation conditions, suggesting that passive familiarisation may recruit a different learning mechanism to that of a more explicit familiarisation experience involving supplementary written information. It appears that decisions regarding resource allocation during subsequent processing of dysarthric speech may be informed by the information afforded by the conditions of familiarisation.
Journal of the Acoustical Society of America, 2012
Differences in perceptual strategies for lexical segmentation of moderate hypokinetic dysarthric ... more Differences in perceptual strategies for lexical segmentation of moderate hypokinetic dysarthric speech, apparently related to the conditions of the familiarization procedure, have been previously reported [Borrie et al., Language and Cognitive Processes (2012)]. The current follow-up investigation examined whether this difference was also observed when familiarization stimuli highlighted syllabic strength contrast cues. Forty listeners completed an identical transcription task following familiarization with dysarthric phrases presented under either passive or explicit learning conditions. Lexical boundary error patterns revealed that syllabic strength cues were exploited in both familiarization conditions. Comparisons with data previously reported afford further insight into perceptual learning of dysarthric speech.
Journal of the Acoustical Society of America, 2013
This investigation examined perceptual learning of dysarthric speech. Forty listeners were random... more This investigation examined perceptual learning of dysarthric speech. Forty listeners were randomly assigned to one of two identification training tasks, aimed at highlighting either the linguistic (word identification task) or indexical (speaker identification task) properties of the neurologically degraded signal. Twenty additional listeners served as a control group, passively exposed to the training stimuli. Immediately following exposure to dysarthric speech, all three listener groups completed an identical phrase transcription task. Analysis of listener transcripts revealed remarkably similar intelligibility improvements for listeners trained to attend to either the linguistic or the indexical properties of the signal. Perceptual learning effects were also evaluated with regards to underlying error patterns indicative of segmental and suprasegmental processing. The findings of this study suggest that elements within both the linguistic and indexical properties of the dysarthric signal are learnable and interact to promote improved processing of this type and severity of speech degradation. Thus, the current study extends support for the development of a model of perceptual processing in which the learning of indexical properties is encoded and retained in conjunction with linguistic properties of the signal.
Journal of Neurological Surgery Part B-Skull Base, 2013
Objectives To determine the pattern of auditory responses, time-course of hearing deterioration, ... more Objectives To determine the pattern of auditory responses, time-course of hearing deterioration, and possible site of lesion following retrosigmoid excision of unilateral vestibular schwannomas. Design Prospective, nonrandomized, observational pilot study. Setting Tertiary referral medical center. Main outcome measures Preoperative and postoperative pure-tone and speech audiometry, auditory brainstem response testing, and distortion product otoacoustic emissions were performed in 20 patients. Testing was conducted every 24 hours for the duration of hospitalization. Transtympanic electrocochleography was performed if delayed deterioration of auditory responses was documented. Results Of the 20 patients, 7 had no discernible cochlear nerve at the end of the procedure. Of the 13 patients with an intact nerve, 6 retained hearing, 3 with evidence of reduced neural function. Of the 7 who lost hearing despite an intact nerve, 5 lost at least cochlear and possibly also neural function, and 1 had reduced neural function but retained cochlear function. There were two examples of delayed deterioration of cochlear nerve responses. Conclusions Hearing loss following retrosigmoid removal of vestibular schwannomas most often involves loss of at least cochlear function, possibly in addition to neural damage. In a smaller number of cases anacusis or hearing deterioration can be attributed to purely neural trauma.
A pilot investigation of dichotic listening of CV stimuli was undertaken using seven adults who s... more A pilot investigation of dichotic listening of CV stimuli was undertaken using seven adults who stutter (AWS) and a comparison group of seven adults who do not stutter (AWNS). The aim of this research was to investigate whether AWS show a difference in the strength of the right ear advantage (REA) in both undirected and directed attention tasks when compared to AWNS. The undirected attention task involved manipulating the interaural intensity difference (IID) of the CV stimuli presented to each ear. The CV stimuli were presented with equal intensity for the directed attention task. The undirected attention results indicated that both AWS and AWNS have a REA for processing speech information, with a primary difference observed between groups in regard to the IID point at which a REA shifts to a LEA. This crossing-over point occurred earlier for AWS, indicating a stronger right hemisphere involvement for the processing of speech compared to AWNS. No differences were found between groups in the directed attention task. The differences and similarities observed in dichotic listening between the two groups are discussed in regard to hemispheric specialization in the processing of speech.
Background/aims. The purpose of this study was to examine characteristics of disfluency clusters ... more Background/aims. The purpose of this study was to examine characteristics of disfluency clusters in adults who stutter (AWS) and to compare these characteristics to those previously reported for children who stutter (CWS). Method. The spontaneous speech of ten AWS was sampled and organized according to utterance length in syllables. The overall number and type of disfluency clusters occurring in each sample were determined. Results. Findings indicated that utterances containing disfluency clusters were significantly longer than fluent utterances, and the occurrence of disfluency clusters was correlated with overall percentage of disfluency. Conclusion. The results obtained in the present study for AWS tend to parallel those found for CWS and serve to validate their occurrence as a feature of the disorder of stuttering.
Journal of Speech, Language, and Hearing Research, 2009
Purpose: The purpose of this study was to determine whether deliberate increases in speaking rate... more Purpose: The purpose of this study was to determine whether deliberate increases in speaking rate would serve to decrease the amount of nasality in the speech of severely hearing-impaired individuals. Method: The participants were 11 severely to profoundly hearing-impaired students, ranging in age from 12 to 19 years (M = 16 years). Each participant provided a baseline speech sample ( R1) followed by 3 training sessions during which participants were trained to increase their speaking rate. Following the training sessions, a second speech sample was obtained ( R2). Acoustic and perceptual analyses of the speech samples obtained at R1 and R2 were undertaken. The acoustic analysis focused on changes in first ( F 1 ) and second ( F 2 ) formant frequency and formant bandwidths. The perceptual analysis involved listener ratings of the speech samples (at R1 and R2) for perceived nasality. Results: Findings indicated a significant increase in speaking rate at R2. In addition, significantly narrower F 2 bandwidth and lower perceptual rating scores of nasality were obtained at R2 across all participants, suggesting a decrease in nasality as speaking rate increases. Conclusion: The nasality demonstrated by hearing-impaired individuals is amenable to change when speaking rate is increased. The influences of speaking rate changes on the perception and production of nasality in hearing-impaired individuals are discussed.
The purpose of this study was to determine whether rising-frequency chirps presented via earphone... more The purpose of this study was to determine whether rising-frequency chirps presented via earphones with an extended high-frequency response would optimize the post-auricular muscle response (PAMR). The PAMR was recorded in adults using three different stimuli (a click, a rising-frequency chirp, and a truncated speech stimulus, /t/). Conventional ER-3A insert earphones were compared to ER-2 insert earphones to determine whether the PAMR is enhanced by the ER-2's extended highfrequency response. There were significant stimulus and earphone effects on PAMR amplitudes. The PAMR was largest for the chirp stimulus and the ER-2 earphones. The poorest responses were obtained using the /t/ stimulus and conventional ER-3A earphones. The results support previous ABR studies that have demonstrated a significant advantage of chirps over clicks for evoked response audiometry, and indicate that the PAMR is enhanced by inclusion of additional high-frequency stimulus energy.
One type of test commonly used to assess auditory processing disorder (APD) is the &a... more One type of test commonly used to assess auditory processing disorder (APD) is the 'filtered words test' (FWT), in which a monaural, low-redundancy speech sample is distorted by using filtering to modify its frequency content. One limitation of the various existing FWTs is that they are performed using a constant level of low-pass filtering, making them prone to ceiling and floor effects that compromise their efficiency and accuracy. A recently developed computer-based test, the University of Canterbury Adaptive Speech Test- Filtered Words (UCAST-FW), uses an adaptive procedure intended to improve the efficiency and sensitivity of the test over its constant-level counterparts. The UCAST-FW was administered to school-aged children to investigate the ability of the test to distinguish between children with and without APD. Fifteen children aged 7-13 diagnosed with APD, and an aged-matched control group of 10 children with no history of listening difficulties. Data obtained demonstrates a significant difference between the UCAST-FW results obtained by children with APD and those with normal auditory processing. These findings provide evidence that the UCAST-FW may discriminate between children with and without APD with greater sensitivity than its constant-level counterparts.
Middle ear sensory information has never been localized in the homunculus of the somatosensory co... more Middle ear sensory information has never been localized in the homunculus of the somatosensory cortex (S1). We investigated the somatosensory representation of the middle ear in 15 normal hearing subjects. We applied small air pressure variations to the tympanic membrane while performing a 3T fMRI study. Unilateral stimulations of the right ear triggered bilateral activations in the caudal part of the postcentral gyrus in Brodmann area 43 (BA 43) and in the auditory associative areas 42 (BA 42) and 22 (BA 22). BA 43 has been found to be involved in activities accompanying oral intake, and could be more largely involved in pressure activities in the oropharynx area. The tympanic membrane is indirectly related to the pharynx area through the action of tensor tympani, which is a Eustachian tube muscle. The Eustachian tube muscles have a role in pressure equalisation in the middle ear and also have a role in the pharyngeal phase of swallowing. Activation of BA 42 and BA 22 could reflect activations associated with the bilateral acoustic reflex triggered prior to selfvocalization to adjust air pressure in the oropharynx during speech. We propose that BA 43, 42 and 22 are the cortical areas associated with middle ear function. We did not find representation of tympanic membrane movements due to pressure in S1, but its representation in the postcentral gyrus in BA 43 seems to suggest that at least part of this area conveys pure somatosensory information.
Journal of speech, language, and hearing research : JSLHR, 2012
PURPOSE: Older adults exhibit difficulty understanding speech that has been experimentally degrad... more PURPOSE: Older adults exhibit difficulty understanding speech that has been experimentally degraded. Age-related changes to the speech mechanism lead to natural degradations in signal quality. We tested the hypothesis that older adults with hearing loss would exhibit declines in speech recognition when listening to the speech of older adults, compared with the speech of younger adults, and would report greater amounts of listening effort in this task. Methods Nineteen individuals with age-related hearing loss completed speech recognition and listening effort scaling tasks. Both were conducted in quiet, when listening to high and low predictability phrases produced by younger and older speakers respectively. RESULTS: No significant difference in speech recognition existed when stimuli were derived from younger or older speakers. However, perceived effort was significantly higher when listening to speech from older adults, as compared to younger adults. CONCLUSIONS: For older individu...
International journal of speech-language pathology, 2012
This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old f... more This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old female following total glossectomy. Speech samples were collected on three occasions within the first 3 months following glossectomy. Vowel articulation was examined acoustically as a function of vowel space and the Euclidean distance separating corner vowels. Perceptual analyses involved presentation of the participant's CV productions to 30 healthy adult listeners who made forced-choice identifications of consonant type. Acoustic analysis revealed improvements in vowel space area and an increase in the Euclidean distances. The perceptual results revealed a statistically significant deterioration in consonants over the 3-month period with anterior sounds being perceived more correctly than medial and posterior sounds. The current study highlights the variable nature of speech following glossectomy, with greater improvements in vowel articulation compared to consonant articulation du...
International journal of pediatric otorhinolaryngology, 2012
OBJECTIVE: One type of test commonly used to examine auditory processing disorders (APD) is the l... more OBJECTIVE: One type of test commonly used to examine auditory processing disorders (APD) is the low-pass filtered speech test (LPFST), of which there are various versions. In LPFSTs, a monaural, low-redundancy speech sample is distorted by using filtering to modify its frequency content. Due to the richness of the neural pathways in the auditory system and the redundancy of acoustic information in spoken language, a normal listener is able to recognize speech even when parts of the signal are missing, whereas this ability is often impaired in listeners with APD. One limitation of the various versions of the LPFST is that they are carried out using a constant level of low-pass filtering (e.g. a fixed 1kHz corner frequency) which makes them prone to ceiling and floor effects. The purpose of this study was to counter these effects by modifying the LPFST using a computer-based adaptive procedure, and to evaluate the performance of normal-hearing participants of varying ages on the test....
Asia Pacific Journal of Speech, Language and Hearing, 2012
... support through the years. My deepest thanks is dedicated to my husband, Mahmood Sahrel Wahid... more ... support through the years. My deepest thanks is dedicated to my husband, Mahmood Sahrel Wahid; my son, Amir Muhammad; my daughter, Nur Maisarah; and my mother, Saadah Abu Bakar. Their patience and love has been a strength for me to complete this thesis. It is my ...
Motor evoked potentials (MEPs) recorded from pharyngeal and anterior hyo-mandibular (submental) m... more Motor evoked potentials (MEPs) recorded from pharyngeal and anterior hyo-mandibular (submental) muscles at rest have been used to evaluate treatment effects on neural pathways underlying swallowing. This study documents a novel methodological approach of recording reliable intra-and inter-session MEPs at the submental muscle group during task-related volitional swallowing. MEPs were elicited by singlepulse transcranial magnetic stimulation (TMS), triggered by a custom-made system when a pre-set level of surface electromyographic activity in the target muscles was breached. Fifteen MEPs were recorded during each of four sessions. Intraclass correlation coefficients (ICCs) were used to assess test-retest reliability within and across sessions for blocks of 3, 5, 10 and 15 trials. Highly reliable intra-session reliability was achieved, maximal for blocks of five trials (0.915). Inter-session reliability varied between 0.474 (three trials per block) and 0.909 (10 trials per block). Surface electromyography-triggered TMS allows reliable measurement of MEP amplitude at the submental muscle group within and across sessions when muscles are pre-activated during volitional swallowing. This methodology will be useful for future investigations on the effects of pathology and modulation of swallowing neural pathways.
International journal of speech-language pathology, 2012
This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old f... more This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old female following total glossectomy. Speech samples were collected on three occasions within the first 3 months following glossectomy. Vowel articulation was examined acoustically as a function of vowel space and the Euclidean distance separating corner vowels. Perceptual analyses involved presentation of the participant's CV productions to 30 healthy adult listeners who made forced-choice identifications of consonant type. Acoustic analysis revealed improvements in vowel space area and an increase in the Euclidean distances. The perceptual results revealed a statistically significant deterioration in consonants over the 3-month period with anterior sounds being perceived more correctly than medial and posterior sounds. The current study highlights the variable nature of speech following glossectomy, with greater improvements in vowel articulation compared to consonant articulation du...
The purpose of this study was to determine whether rising-frequency chirps presented via earphone... more The purpose of this study was to determine whether rising-frequency chirps presented via earphones with an extended high-frequency response would optimize the post-auricular muscle response (PAMR). The PAMR was recorded in adults using three different stimuli (a click, a rising-frequency chirp, and a truncated speech stimulus, /t/). Conventional ER-3A insert earphones were compared to ER-2 insert earphones to determine whether the PAMR is enhanced by the ER-2's extended highfrequency response. There were significant stimulus and earphone effects on PAMR amplitudes. The PAMR was largest for the chirp stimulus and the ER-2 earphones. The poorest responses were obtained using the /t/ stimulus and conventional ER-3A earphones. The results support previous ABR studies that have demonstrated a significant advantage of chirps over clicks for evoked response audiometry, and indicate that the PAMR is enhanced by inclusion of additional high-frequency stimulus energy.
We follow up on research demonstrating that aero-tactile in- formation can enhance or interfere w... more We follow up on research demonstrating that aero-tactile in- formation can enhance or interfere with accurate auditory per- ception among uninformed and untrained perceivers [1, 2, 3]. We computationally extract aperiodic information from audi- tory recordings of speech, which represents turbulent air-flow produced from the lips [4, 5]. This extracted signal is used to drive a piezoelectric air-pump producing air-flow to the right temple simultaneous with presentation of auditory recordings. Using forced-choice experiments, we replicate previous results with stops, finding enhanced perception of /pa/ in /pa/ vs. /ba/ pairs, and /ta/ in /ta/ vs. /da/ pairs [1, 6, 2, 3]. We also found enhanced perception of /fa/ in /ba/ vs. /fa/ pairs, and /sha/ in /da/ vs. /sha/ pairs, demonstrating that air flow during fricative pro- duction contacting the skin can also enhance speech perception. The results show that aero-tactile information can be extracted from the audio signal and used to enhance speech perception of a large class of speech sounds found in many languages of the world.
To explore medical oncologists' and audiologists' knowledge and attitudes regarding ototo... more To explore medical oncologists' and audiologists' knowledge and attitudes regarding ototoxicity monitoring, and to gain an understanding of monitoring currently being implemented at District Health Boards (DHBs) nationwide. We also aimed to identify ways in which audiological outcomes for patients receiving potentially ototoxic treatments could be improved, including examining whether the formulation and implementation of a national ototoxicity monitoring guideline is necessary.
This paper evaluated the diagnostic power of electrocochleography (ECochG) in detecting Ménière's... more This paper evaluated the diagnostic power of electrocochleography (ECochG) in detecting Ménière's disease (MD) as compared with two subjective assessment methods, including the clinical guidelines provided by the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing Equilibrium and the Gibson score. A retrospective study of 250 suspected MD cases was conducted. The agreement between the three assessment methods was found to be relatively high, with a total reliability being higher than 70%. Participants who tested "positive" with ECochG exhibited a higher occurrence rate of asymmetric hearing threshold as well as the four MD symptoms, namely, vertigo, hearing loss, tinnitus, and aural fullness. The "positive" ECochG group also showed a high correlation between the ECochG measures in response to stimuli at adjacent frequency ranges, suggesting that the interfrequency ECochG correspondence may be sensitive to the presence of endolymphatic hydrops and thus may serve as a useful diagnostic marker for MD.
This investigation evaluated the familiarisation conditions required to promote subsequent and mo... more This investigation evaluated the familiarisation conditions required to promote subsequent and more long-term improvements in perceptual processing of dysarthric speech and examined the cognitive-perceptual processes that may underlie the experience-evoked learning response. Sixty listeners were randomly allocated to one of three experimental groups and were familiarised under the following conditions: (1) neurologically intact speech (control), (2) dysarthric speech (passive familiarisation), and (3) dysarthric speech coupled with written information (explicit familiarisation). All listeners completed an identical phrase transcription task immediately following familiarisation, and listeners familiarised with dysarthric speech also completed a follow-up phrase transcription task 7 days later. Listener transcripts were analysed for a measure of intelligibility (percent words correct), as well as error patterns at a segmental (percent syllable resemblance) and suprasegmental (lexical boundary errors) level of perceptual processing. The study found that intelligibility scores for listeners familiarised with dysarthric speech were significantly greater than those of the control group, with the greatest and most robust gains afforded by the explicit familiarisation condition. Relative perceptual gains in detecting phonetic and prosodic aspects of the signal varied dependent upon the familiarisation conditions, suggesting that passive familiarisation may recruit a different learning mechanism to that of a more explicit familiarisation experience involving supplementary written information. It appears that decisions regarding resource allocation during subsequent processing of dysarthric speech may be informed by the information afforded by the conditions of familiarisation.
Journal of the Acoustical Society of America, 2012
Differences in perceptual strategies for lexical segmentation of moderate hypokinetic dysarthric ... more Differences in perceptual strategies for lexical segmentation of moderate hypokinetic dysarthric speech, apparently related to the conditions of the familiarization procedure, have been previously reported [Borrie et al., Language and Cognitive Processes (2012)]. The current follow-up investigation examined whether this difference was also observed when familiarization stimuli highlighted syllabic strength contrast cues. Forty listeners completed an identical transcription task following familiarization with dysarthric phrases presented under either passive or explicit learning conditions. Lexical boundary error patterns revealed that syllabic strength cues were exploited in both familiarization conditions. Comparisons with data previously reported afford further insight into perceptual learning of dysarthric speech.
Journal of the Acoustical Society of America, 2013
This investigation examined perceptual learning of dysarthric speech. Forty listeners were random... more This investigation examined perceptual learning of dysarthric speech. Forty listeners were randomly assigned to one of two identification training tasks, aimed at highlighting either the linguistic (word identification task) or indexical (speaker identification task) properties of the neurologically degraded signal. Twenty additional listeners served as a control group, passively exposed to the training stimuli. Immediately following exposure to dysarthric speech, all three listener groups completed an identical phrase transcription task. Analysis of listener transcripts revealed remarkably similar intelligibility improvements for listeners trained to attend to either the linguistic or the indexical properties of the signal. Perceptual learning effects were also evaluated with regards to underlying error patterns indicative of segmental and suprasegmental processing. The findings of this study suggest that elements within both the linguistic and indexical properties of the dysarthric signal are learnable and interact to promote improved processing of this type and severity of speech degradation. Thus, the current study extends support for the development of a model of perceptual processing in which the learning of indexical properties is encoded and retained in conjunction with linguistic properties of the signal.
Journal of Neurological Surgery Part B-Skull Base, 2013
Objectives To determine the pattern of auditory responses, time-course of hearing deterioration, ... more Objectives To determine the pattern of auditory responses, time-course of hearing deterioration, and possible site of lesion following retrosigmoid excision of unilateral vestibular schwannomas. Design Prospective, nonrandomized, observational pilot study. Setting Tertiary referral medical center. Main outcome measures Preoperative and postoperative pure-tone and speech audiometry, auditory brainstem response testing, and distortion product otoacoustic emissions were performed in 20 patients. Testing was conducted every 24 hours for the duration of hospitalization. Transtympanic electrocochleography was performed if delayed deterioration of auditory responses was documented. Results Of the 20 patients, 7 had no discernible cochlear nerve at the end of the procedure. Of the 13 patients with an intact nerve, 6 retained hearing, 3 with evidence of reduced neural function. Of the 7 who lost hearing despite an intact nerve, 5 lost at least cochlear and possibly also neural function, and 1 had reduced neural function but retained cochlear function. There were two examples of delayed deterioration of cochlear nerve responses. Conclusions Hearing loss following retrosigmoid removal of vestibular schwannomas most often involves loss of at least cochlear function, possibly in addition to neural damage. In a smaller number of cases anacusis or hearing deterioration can be attributed to purely neural trauma.
A pilot investigation of dichotic listening of CV stimuli was undertaken using seven adults who s... more A pilot investigation of dichotic listening of CV stimuli was undertaken using seven adults who stutter (AWS) and a comparison group of seven adults who do not stutter (AWNS). The aim of this research was to investigate whether AWS show a difference in the strength of the right ear advantage (REA) in both undirected and directed attention tasks when compared to AWNS. The undirected attention task involved manipulating the interaural intensity difference (IID) of the CV stimuli presented to each ear. The CV stimuli were presented with equal intensity for the directed attention task. The undirected attention results indicated that both AWS and AWNS have a REA for processing speech information, with a primary difference observed between groups in regard to the IID point at which a REA shifts to a LEA. This crossing-over point occurred earlier for AWS, indicating a stronger right hemisphere involvement for the processing of speech compared to AWNS. No differences were found between groups in the directed attention task. The differences and similarities observed in dichotic listening between the two groups are discussed in regard to hemispheric specialization in the processing of speech.
Background/aims. The purpose of this study was to examine characteristics of disfluency clusters ... more Background/aims. The purpose of this study was to examine characteristics of disfluency clusters in adults who stutter (AWS) and to compare these characteristics to those previously reported for children who stutter (CWS). Method. The spontaneous speech of ten AWS was sampled and organized according to utterance length in syllables. The overall number and type of disfluency clusters occurring in each sample were determined. Results. Findings indicated that utterances containing disfluency clusters were significantly longer than fluent utterances, and the occurrence of disfluency clusters was correlated with overall percentage of disfluency. Conclusion. The results obtained in the present study for AWS tend to parallel those found for CWS and serve to validate their occurrence as a feature of the disorder of stuttering.
Journal of Speech, Language, and Hearing Research, 2009
Purpose: The purpose of this study was to determine whether deliberate increases in speaking rate... more Purpose: The purpose of this study was to determine whether deliberate increases in speaking rate would serve to decrease the amount of nasality in the speech of severely hearing-impaired individuals. Method: The participants were 11 severely to profoundly hearing-impaired students, ranging in age from 12 to 19 years (M = 16 years). Each participant provided a baseline speech sample ( R1) followed by 3 training sessions during which participants were trained to increase their speaking rate. Following the training sessions, a second speech sample was obtained ( R2). Acoustic and perceptual analyses of the speech samples obtained at R1 and R2 were undertaken. The acoustic analysis focused on changes in first ( F 1 ) and second ( F 2 ) formant frequency and formant bandwidths. The perceptual analysis involved listener ratings of the speech samples (at R1 and R2) for perceived nasality. Results: Findings indicated a significant increase in speaking rate at R2. In addition, significantly narrower F 2 bandwidth and lower perceptual rating scores of nasality were obtained at R2 across all participants, suggesting a decrease in nasality as speaking rate increases. Conclusion: The nasality demonstrated by hearing-impaired individuals is amenable to change when speaking rate is increased. The influences of speaking rate changes on the perception and production of nasality in hearing-impaired individuals are discussed.
The purpose of this study was to determine whether rising-frequency chirps presented via earphone... more The purpose of this study was to determine whether rising-frequency chirps presented via earphones with an extended high-frequency response would optimize the post-auricular muscle response (PAMR). The PAMR was recorded in adults using three different stimuli (a click, a rising-frequency chirp, and a truncated speech stimulus, /t/). Conventional ER-3A insert earphones were compared to ER-2 insert earphones to determine whether the PAMR is enhanced by the ER-2's extended highfrequency response. There were significant stimulus and earphone effects on PAMR amplitudes. The PAMR was largest for the chirp stimulus and the ER-2 earphones. The poorest responses were obtained using the /t/ stimulus and conventional ER-3A earphones. The results support previous ABR studies that have demonstrated a significant advantage of chirps over clicks for evoked response audiometry, and indicate that the PAMR is enhanced by inclusion of additional high-frequency stimulus energy.
One type of test commonly used to assess auditory processing disorder (APD) is the &a... more One type of test commonly used to assess auditory processing disorder (APD) is the 'filtered words test' (FWT), in which a monaural, low-redundancy speech sample is distorted by using filtering to modify its frequency content. One limitation of the various existing FWTs is that they are performed using a constant level of low-pass filtering, making them prone to ceiling and floor effects that compromise their efficiency and accuracy. A recently developed computer-based test, the University of Canterbury Adaptive Speech Test- Filtered Words (UCAST-FW), uses an adaptive procedure intended to improve the efficiency and sensitivity of the test over its constant-level counterparts. The UCAST-FW was administered to school-aged children to investigate the ability of the test to distinguish between children with and without APD. Fifteen children aged 7-13 diagnosed with APD, and an aged-matched control group of 10 children with no history of listening difficulties. Data obtained demonstrates a significant difference between the UCAST-FW results obtained by children with APD and those with normal auditory processing. These findings provide evidence that the UCAST-FW may discriminate between children with and without APD with greater sensitivity than its constant-level counterparts.
Middle ear sensory information has never been localized in the homunculus of the somatosensory co... more Middle ear sensory information has never been localized in the homunculus of the somatosensory cortex (S1). We investigated the somatosensory representation of the middle ear in 15 normal hearing subjects. We applied small air pressure variations to the tympanic membrane while performing a 3T fMRI study. Unilateral stimulations of the right ear triggered bilateral activations in the caudal part of the postcentral gyrus in Brodmann area 43 (BA 43) and in the auditory associative areas 42 (BA 42) and 22 (BA 22). BA 43 has been found to be involved in activities accompanying oral intake, and could be more largely involved in pressure activities in the oropharynx area. The tympanic membrane is indirectly related to the pharynx area through the action of tensor tympani, which is a Eustachian tube muscle. The Eustachian tube muscles have a role in pressure equalisation in the middle ear and also have a role in the pharyngeal phase of swallowing. Activation of BA 42 and BA 22 could reflect activations associated with the bilateral acoustic reflex triggered prior to selfvocalization to adjust air pressure in the oropharynx during speech. We propose that BA 43, 42 and 22 are the cortical areas associated with middle ear function. We did not find representation of tympanic membrane movements due to pressure in S1, but its representation in the postcentral gyrus in BA 43 seems to suggest that at least part of this area conveys pure somatosensory information.
Journal of speech, language, and hearing research : JSLHR, 2012
PURPOSE: Older adults exhibit difficulty understanding speech that has been experimentally degrad... more PURPOSE: Older adults exhibit difficulty understanding speech that has been experimentally degraded. Age-related changes to the speech mechanism lead to natural degradations in signal quality. We tested the hypothesis that older adults with hearing loss would exhibit declines in speech recognition when listening to the speech of older adults, compared with the speech of younger adults, and would report greater amounts of listening effort in this task. Methods Nineteen individuals with age-related hearing loss completed speech recognition and listening effort scaling tasks. Both were conducted in quiet, when listening to high and low predictability phrases produced by younger and older speakers respectively. RESULTS: No significant difference in speech recognition existed when stimuli were derived from younger or older speakers. However, perceived effort was significantly higher when listening to speech from older adults, as compared to younger adults. CONCLUSIONS: For older individu...
International journal of speech-language pathology, 2012
This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old f... more This study involved an acoustic and perceptual analysis of the speech produced by a 31-year-old female following total glossectomy. Speech samples were collected on three occasions within the first 3 months following glossectomy. Vowel articulation was examined acoustically as a function of vowel space and the Euclidean distance separating corner vowels. Perceptual analyses involved presentation of the participant's CV productions to 30 healthy adult listeners who made forced-choice identifications of consonant type. Acoustic analysis revealed improvements in vowel space area and an increase in the Euclidean distances. The perceptual results revealed a statistically significant deterioration in consonants over the 3-month period with anterior sounds being perceived more correctly than medial and posterior sounds. The current study highlights the variable nature of speech following glossectomy, with greater improvements in vowel articulation compared to consonant articulation du...
International journal of pediatric otorhinolaryngology, 2012
OBJECTIVE: One type of test commonly used to examine auditory processing disorders (APD) is the l... more OBJECTIVE: One type of test commonly used to examine auditory processing disorders (APD) is the low-pass filtered speech test (LPFST), of which there are various versions. In LPFSTs, a monaural, low-redundancy speech sample is distorted by using filtering to modify its frequency content. Due to the richness of the neural pathways in the auditory system and the redundancy of acoustic information in spoken language, a normal listener is able to recognize speech even when parts of the signal are missing, whereas this ability is often impaired in listeners with APD. One limitation of the various versions of the LPFST is that they are carried out using a constant level of low-pass filtering (e.g. a fixed 1kHz corner frequency) which makes them prone to ceiling and floor effects. The purpose of this study was to counter these effects by modifying the LPFST using a computer-based adaptive procedure, and to evaluate the performance of normal-hearing participants of varying ages on the test....
Asia Pacific Journal of Speech, Language and Hearing, 2012
... support through the years. My deepest thanks is dedicated to my husband, Mahmood Sahrel Wahid... more ... support through the years. My deepest thanks is dedicated to my husband, Mahmood Sahrel Wahid; my son, Amir Muhammad; my daughter, Nur Maisarah; and my mother, Saadah Abu Bakar. Their patience and love has been a strength for me to complete this thesis. It is my ...
Motor evoked potentials (MEPs) recorded from pharyngeal and anterior hyo-mandibular (submental) m... more Motor evoked potentials (MEPs) recorded from pharyngeal and anterior hyo-mandibular (submental) muscles at rest have been used to evaluate treatment effects on neural pathways underlying swallowing. This study documents a novel methodological approach of recording reliable intra-and inter-session MEPs at the submental muscle group during task-related volitional swallowing. MEPs were elicited by singlepulse transcranial magnetic stimulation (TMS), triggered by a custom-made system when a pre-set level of surface electromyographic activity in the target muscles was breached. Fifteen MEPs were recorded during each of four sessions. Intraclass correlation coefficients (ICCs) were used to assess test-retest reliability within and across sessions for blocks of 3, 5, 10 and 15 trials. Highly reliable intra-session reliability was achieved, maximal for blocks of five trials (0.915). Inter-session reliability varied between 0.474 (three trials per block) and 0.909 (10 trials per block). Surface electromyography-triggered TMS allows reliable measurement of MEP amplitude at the submental muscle group within and across sessions when muscles are pre-activated during volitional swallowing. This methodology will be useful for future investigations on the effects of pathology and modulation of swallowing neural pathways.
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Papers by Greg O'Beirne