Kathy Y. S. Lee

Tone discrimination in Cantonese-speaking children using a cochlear implant

Most tone perception tests for Cantonese-speaking cochlear implant users have been based on tone identification tasks which require significant cognitive development to be successfully completed. Results from such tests suggest that cochlear implant child users are performing at about chance level and may not be receiving much information about pitch using the implant. This paper reports on the ability of cochlear implant child users to discriminate pitch variations in Cantonese by using an experimental procedure based on play audiometry. As part of the study, the usefulness of higher rates of electrode stimulation for aiding tone discrimination is also examined. Cochlear implant users are shown to derive sufficient information about pitch to discriminate most tone contrasts relatively successfully, with performance being most variable for contrasts involving tones clustered in the lower register of the speakers fundamental frequency range. Contrary to hypothesis, higher electrode stimulation rates are not found to offer significant benefits for aiding pitch discrimination.

Tone Perception Ability of Cantonese-Speaking Children

Studies have shown that while children acquire all Cantonese tones by age two, they are not able to label them reliably until approximately age 10. One possible explanation for the large age discrepancy may be the different methodologies used. This study aimed to (1) investigate a new research design for the collection of reliable tone perception data from young children; (2) compare lexical and nonlexical items for testing tone perception ability; and (3) identify the relative ease of perceiving the three basic tone contrasts in Cantonese, that is, high level/high rising (T1/T2), high level/low falling (T1/T4), and, high rising/low falling tones (T2/T4). The three tone pairs were presented to 31 children in the form of word and nonword stimuli. It was found that the research design could be used to assess the tone perception knowledge of children as young as 2;09. Significant differences were found between word and nonword stimuli and also in the identification of the T2/T4 contrast in comparison with the other two pairs. Childrens overall tone perception abilities are discussed in detail with reference to the role of lexical knowledge and the potential for tone perception confusions arising from differences in fundamental frequencies for tone onset and offset.Studies have shown that while children acquire all Cantonese tones by age two, they are not able to label them reliably until approximately age 10. One possible explanation for the large age discrepancy may be the different methodologies used. This study aimed to (1) investigatea new research design for the collection of reliable tone perception data from young children; (2) compare lexical and nonlexical items for testing tone perception ability; and (3) identify the relative ease of perceiving the three basic tone contrasts in Cantonese, that is, high level/high rising (T1 /T2), high level/low falling (T1/T4), and, high rising/low falling tones (T2/T4). The three tone pairs were presented to 31 children in the form of word and nonword stimuli. It was found that the research design could be used to assess the tone perception knowledge of children as young as 2;09. Significant differences were found between word and nonword stimuli and also in the identification of the T2/T4 contrast in comparison with the other two pairs. Childrens overall tone perception abilities are discussed in detail with reference to the role of lexical knowledge and the potential for tone perception confusions arising from differences in fundamental frequencies for tone onset and offset.

The development of the 'Cantonese Receptive Vocabulary Test' for children aged 2-6 in Hong Kong

The study aims to develop a Cantonese receptive vocabulary test to assess 2-6-year-old children in Hong Kong. The test consists of 100 test items. Each target item is accompanied by a phonological distractor, a semantic distractor and an unrelated distractor. A sample of 609 normal children from four Maternal and Child Health Centres and nine kindergartens was selected. The results show that there is a significant effect of age on the correct score. ANOVA was performed to look at the age effect on each distractor individually. It was found that the scores of the three distractors decrease in their own patterns as age increases. With strong content validity, strong construct validity and high correlation coefficients in the split-half reliability, this test could be used as a reliable measurement for the Cantonese-speaking population in Hong Kong.

Spoken word recognition in children with cochlear implants : A five-year study on speakers of a tonal language

Objectives: To study the effects of age at implantation and duration of implant use on the performance of spoken word recognition of pediatric cochlear implantees in a tonal language setting over a period of 5 years. Design: Sixty-four children, given implants between the ages 1:01 and 14:09 (years:months), were divided into three age groups. They were tested on open-set word recognition ability at seven time intervals from before surgery to 5 years after surgery. Analyses of variance with repeated measurements were used to examine the effect of their age at implantation and the duration of implant use. Results: Duration of implant experience was significant in spoken word recognition across the three age groups (p < 0.01). Children given implants below the age of 3 years caught up with the performance of the older children at 12 months after implantation. The difference in score reached statistical significance at 2 and at 3 years after surgery (p = 0.03, p = 0.00). Conclusions: The performance of Cantonese-speaking children was similar to that of English-speaking children in that better outcomes were associated with longer implant experience as well as when implantation occurred at a younger age. The children implanted before the age of 3 and who had an implant experience of more than 2 years outperformed the children who were given implants after the age of 6 and also sustained these higher scores throughout 5 years of postimplant testing.

Laryngopharyngeal sensory deficits and impaired pharyngeal motor function predict aspiration in patients irradiated for nasopharyngeal carcinoma.

To assess the contribution of laryngopharyngeal sensory deficits and impaired pharyngeal motor function to aspiration in patients irradiated for nasopharyngeal carcinoma.

Comparison of Rater's reliability on perceptual evaluation of different types of voice sample.

OBJECTIVE/HYPOTHESIS The objective of this study was to determine whether different types of voice samples affect rater reliability and which type of sample can be rated most reliably, with particular reference to two types of connected speech-passage reading and conversational speech. STUDY DESIGN Prospective reliability study. METHODS One hundred fifty voice samples from 40 speakers were presented to 14 speech pathologists experienced in managing voice disorders. Each speaker contributed three types of voice samples: sustained vowels, passage reading, and conversational speech. Ratings were made on four vocal parameters--overall severity, roughness, breathiness, and strain--on a 10-point equal-appearing interval scale. RESULTS Differences in intrarater reliability across the three types of voice samples were noted. Higher intrarater reliability was achieved with connected speech than with sustained vowel samples. Interrater reliability showed no statistically significant difference across the three types but increased with the severity of dysphonia. CONCLUSIONS This study reveals that raters give internally more reliable ratings for connected speech samples. Results also indicate that voices with severe disorders appear to be rated more reliably.

Lexical tone perception ability of profoundly hearing-impaired children: performance of cochlear implant and hearing aid users.

Objective: In tone languages such as Cantonese, a change in tone denotes a change in lexical meaning. The present study investigates the functional benefit of hearing devices in assisting tone perception among children with profound hearing impairment. Subjects: Fifty-two children with profound hearing loss were categorized into two groups based on their primary type of hearing device - a hearing aid group and cochlear implant group. Methods: A 75-item tone identification test covering all 15 Cantonese tone contrast pairs was administered to each subject under two conditions - unaided (hearing devices turned off) and aided (devices turned on). The proportion of correct responses was computed as the total score for all items and subtotal contrast scores for each of the 15 tone contrasts. Results: The results indicated no significant differences between the children wearing hearing aids and those with cochlear implants under the unaided or the aided condition (z = −0.91, p = 0.36; z = −0.40, p = 0.69, respectively). Regardless of the type of device used, the total scores under the aided condition were higher than those under the unaided condition (z = −3.55 for the hearing aid group; z = −4.87 for the cochlear implant group, both ps < 0.01). Conclusion: Children wearing hearing devices generally have a satisfactory functional gain in tone perception. No major observable difference was noted between children using cochlear implants and those using hearing aids. Tone contrast pairs with dissimilar fundamental frequency at onset and dissimilar tone contour patterns were more easily identified.

Automatic speech recognition for acoustical analysis and assessment of cantonese pathological voice and speech

This paper describes the application of state-of-the-art automatic speech recognition (ASR) systems to objective assessment of voice and speech disorders. Acoustical analysis of speech has long been considered a promising approach to non-invasive and objective assessment of people. In the past the types and amount of speech materials used for acoustical assessment were very limited. With the ASR technology, we are able to perform acoustical and linguistic analyses with a large amount of natural speech from impaired speakers. The present study is focused on Cantonese, which is a major Chinese dialect. Two representative disorders of speech production are investigated: dysphonia and aphasia. ASR experiments are carried out with continuous and spontaneous speech utterances from Cantonese-speaking patients. The results confirm the feasibility and potential of using natural speech for acoustical assessment of voice and speech disorders, and reveal the challenging issues in acoustic modeling and language modeling of pathological speech.

Lexical tone perception in native speakers of Cantonese

Abstract Purpose. This study aimed at investigating (1) tone perception development among typically-developing Cantonese speakers and (2) the hierarchy of tone perception difficulty among the 15 tone contrasts. Method. Two-hundred typically-developing children aged 3–10 and a group of 25 normal hearing adults were recruited. They were tested on a pool of 75-item calibrated recorded speech signals. Participants responded to each stimulus by pointing at the corresponding picture displayed on a computer screen from a choice of four. Result. There was a gradual increase in tone perception accuracy from children aged 3–6. After age 6, tone perception accuracy was similar to adults with an average error rate of 3–8%. The two tone contrasts that listeners consistently found difficult to distinguish were T2T5 (high-rising vs low-rising) and T3T6 (mid-level vs low-level). In addition, all children groups also showed difficulty in T4T6 identification (low-falling vs low-level). Conclusion. Tone perception is not error-free even among native Cantonese-speaking adults. Overall tone identification performance improved steadily from age 3 to age 6. Based on the participants’ performance, a three-tier set of tone groups, with an increasing level of difficulty for identification, is proposed for rehabilitation purposes. These tone groups are (1) Easy: T1T2, T1T3, T1T4, T1T5, T1T6, and T2T3, (2) Medium: T2T4, T2T6, T3T4, and T4T5, and (3) Hard: T2T5, T3T5, T3T6, T4T6, and T5T6.

Age sensitivity in the acquisition of lexical tone production: evidence from children with profound congenital hearing impairment after cochlear implantation.

Objectives: This study investigated the effects of implant experience and age at implantation on the Cantonese tone production of children with cochlear implants. The study also examined whether there was a particular age at which children were more responsive to acquiring tones. Methods: The study included 45 children who had received unilateral cochlear implants at a mean age of 65.56 months. The subjects were grouped according to their age at cochlear implantation and were assessed annually for 5 years thereafter. A picture-naming task was used to measure their tone production performance. Results: A simple effect of age at implantation was significant at all testing intervals except at the preoperative data point. Children who were younger than 4 years of age when they received their implants scored significantly higher than did the 2 older groups at various testing intervals. A significant simple effect of implant experience was also found. Progress was most striking in children who received their implants before the age of 4 years. Conclusions: For the most effective acquisition of Cantonese lexical tones, children should undergo early cochlear implantation. For children who receive implants before the age of 4 years, benefits are noted in tone production ability in terms of a faster rate of improvement within a shorter period of time.