Tone production ability in Cantonese-speaking hearing- impaired children with cochlear implants or hearing aids

A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2007.Thesis (B.Sc)--University of Hong Kong, 2007.Also available in print.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Mandarin speech perception in combined electric and acoustic stimulation.

For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI) and hearing aid (HA) typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0) information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2) information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects' HA-aided pure-tone average (PTA) thresholds between 250 and 2000 Hz; subjects were divided into two groups: "better" PTA (<50 dB HL) or "poorer" PTA (>50 dB HL). The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12), further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception

Consonant discrimination by Mandarin-speaking children with prelingual hearing impairment

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Deafness and Orality: An Electronic Conversation

Processing Note: This is a symposium and has a lot of participants, listed as authors and recorded here in alphabetical order.AbstractNot

Acoustic cues to tonal contrasts in Mandarin: Implications for cochlear implants

The present study systematically manipulated three acoustic cues-fundamental frequency (f0), amplitude envelope, and duration-to investigate their contributions to tonal contrasts in Mandarin. Simplified stimuli with all possible combinations of these three cues were presented for identification to eight normal-hearing listeners, all native speakers of Mandarin from Taiwan. The f0 information was conveyed either by an f0-controlled sawtooth carrier or a modulated noise so as to compare the performance achievable by a clear indication of voice f0 and what is possible with purely temporal coding of f0. Tone recognition performance with explicit f0 was much better than that with any combination of other acoustic cues (consistently greater than 90% correct compared to 33%-65%; chance is 25%). In the absence of explicit f0, the temporal coding of f0 and amplitude envelope both contributed somewhat to tone recognition, while duration had only a marginal effect. Performance based on these secondary cues varied greatly across listeners. These results explain the relatively poor perception of tone in cochlear implant users, given that cochlear implants currently provide only weak cues to f0, so that users must rely upon the purely temporal (and secondary) features for the perception of tone. (c) 2008 Acoustical Society of America

The effect of timbre and pitch-pattern difficulty on the pitch perceptions of elementary-aged users of cochlear implants

The purpose of this study was to examine the effects of timbre and pitch-pattern difficulty on perceptions of same-difference between paired pitch patterns, altered and unaltered by timbre and pattern difficulty, among elementary-aged users of cochlear implants. Three null hypotheses were tested to determine the significance of these variables and their interaction on the pitch perceptions of children aged five through twelve, who used cochlear implants. Secondary purposes of the study included the examination of the relationships, if any, between age, age at implantation, and whether there were significant differences between participants' speech processor and pitch perceptions. The Adapted Musical Background Questionnaire was completed by each participant/parent(s)/guardian(s) and used to collect information about each participants' hearing history and musical experiences. The Pitch Discrimination Test, (PDT) was a researcher-developed, 36-item data collection instrument used to measure pitch perceptions of participants. Three timbres were used as stimuli, including the soprano voice, piano, and violin. Thirteen participant responses to the PDT were recorded individually. Results were analyzed using IBM© SPSS© Statistics Version 22. Results of the study revealed no effect of timbre (p = .511), or pitch-pattern difficulty (p = .971) on pitch perceptions. A significant interaction between timbre and pitch-pattern difficulty, however, was found (p = .046). Additional analyses revealed that there were significant differences between mean scores of PDT test items presented by violin and soprano voice for difficult patterns (p = .041), and items presented by soprano and piano for patterns with moderate difficulty (p = .041). The participants discriminated difficult patterns more accurately when the PDT items were presented by soprano voice than piano, but participants discriminated moderate patterns more accurately when the PDT items were presented piano than by soprano voice. There were no significant positive or negative correlations between age or age at implantation and PDT scores. Additionally, there were no significant differences between participant scores on the PDT and the type of speech processor used. Participants who used CochlearTM devices, however, had higher average scores than participants who used MED-EL® devices. Recommendations were suggested for future research and instruction of children who use cochlear implants in the elementary general music classroom

Hearing Disorders: Diagnosis, Management, and Future Opportunities

This book focuses on research on sensorineural hearing loss, syndromic or non-syndromic, related to genetic and viral factors. The metabolic syndrome, autoimmune etiopathogenesis, and new elements of cochlear implantation were also evaluated. New developments and utility of laboratory tests in inner ear diseases (sudden sensorineural hearing loss, Meniere disease, benign paroxysmal positional vertigo, vestibular neuritis) are also discussed

The perception and production of stress and intonation by children with cochlear implants

Users of current cochlear implants have limited access to pitch information and hence to intonation in speech. This seems likely to have an important impact on prosodic perception. This thesis examines the perception and production of the prosody of stress in children with cochlear implants. The interdependence of perceptual cues to stress (pitch, timing and loudness) in English is well documented and each of these is considered in analyses of both perception and production. The subject group comprised 17 implanted (CI) children aged 5;7 to 16;11 and using ACE or SPEAK processing strategies. The aims are to establish (i) the extent to which stress and intonation are conveyed to CI children in synthesised bisyllables (BAba vs. baBA) involving controlled changes in F0, duration and amplitude (Experiment I), and in natural speech involving compound vs. phrase stress and focus (Experiment II). (ii) when pitch cues are missing or are inaudible to the listeners, do other cues such as loudness or timing contribute to the perception of stress and intonation? (iii) whether CI subjects make appropriate use of F0, duration and amplitude to convey linguistic focus in speech production (Experiment III). Results of Experiment I showed that seven of the subjects were unable to reliably hear pitch differences of 0.84 octaves. Most of the remaining subjects required a large (approx 0.5 octave) difference to reliably hear a pitch change. Performance of the CI children was poorer than that of a normal hearing group of children presented with an acoustic cochlear implant simulation. Some of the CI children who could not discriminate F0 differences in Experiment I nevertheless scored above chance in tests involving focus in natural speech in Experiment II. Similarly, some CI subjects who were above chance in the production of appropriate F0 contours in Experiment III could not hear F0 differences of 0.84 octaves. These results suggest that CI children may not necessarily rely on F0 cues to stress, and in the absence of F0 or amplitude cues, duration may provide an alternative cue

Fricatives, affricates, and vowels in Cantonese-speaking children with cochlear implants : an acoustic study

The aim of the present study was to acoustically analyze speech performance of Cantonese-speaking children with cochlear implants over a three-month period, and compare it with that of the hearing controls. Three categories of sounds in Cantonese were focused: vowels /i/, /ɛ/, /a/, /ɔ/ and /u/ (first and second formant frequencies), fricatives /s/ and /f/ (noise centre of gravity), and affricates /ts/ and /tsh/ (accuracy, production pattern and duration). Twenty-one subjects with cochlear implants and 21 hearing subjects matched with age and gender were recruited. Speech samples were recorded and analyzed. The results showed that children with cochlear implants demonstrated statistically significant deviated performance for vowels, fricatives, and affricates when compared with the hearing controls. However, children with cochlear implants showed an overall improvement in speech performance for all the sound categories at the second recording. The results supported that prolonged use of cochlear implants brings beneficial effect.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science