Edwin M.-L. Yiu

Impact and prevention of voice problems in the teaching profession: embracing the consumers' view.

Teachers are vulnerable to developing voice problems due to their specific occupational demands during teaching. Information on how the teaching profession is impacted by voice problems and what the profession perceives to be useful information for preventing voice problems is important for health care service providers. A total of 122 subjects from the teaching profession (55 practicing teachers and 67 prospective teachers) were therefore surveyed to ascertain their perception of their voice condition and the impact of voice problems on their communication, social life, personal emotions, and occupation. The results showed that the practicing teachers perceived their voice to be significantly worse than the prospective teachers. In addition, the teachers also faced significantly more difficulties in their daily communication than the prospective teachers. These two groups of subjects believed that information on breathing exercises and specific vocal hygiene strategies would help them prevent voice problems.

Linguistic assessment of Chinese-speaking aphasics: Development of a Cantonese aphasia battery

Abstract The characteristics of Chinese being a logographic and tonal language has often made it attractive for research. In particular, the right hemisphere has been postulated to be more important in Chinese because of its superiority in prosody and visuo-spatial processing. Literature on Chinese-speaking aphasia is usually single case studies and without a standardised assessment protocol, comparison across studies would be difficult. This study reports the development of a Chinese aphasia test battery with quantitative criteria. It aims at providing clinicians and researchers with guided comprehensive survey of language skills in Chinese (Cantonese). Language performance of 51 Chinese (Cantonese)- speaking aphasic subjects were reported. All of the subjects had aphasias following left hemisphere damage. The classical aphasia patterns of Indo-European language speakers were readily demonstrated in these Chinese-speaking subjects.

Effect of hydration and vocal rest on the vocal fatigue in amateur karaoke singers.

Karaoke singing is a very popular entertainment among young people in Asia. It is a leisure singing activity with the singers voice amplified with special acoustic effects in the backdrop of music. Music video and song captions are shown on television screen to remind the singers during singing. It is not uncommon to find participants singing continuously for four to five hours each time. As most of the karaoke singers have no formal training in singing, these amateur singers are more vulnerable to developing voice problems under these intensive singing activities. This study reports the performance of 20 young amateur singers (10 males and 10 females, aged between 20-25 years) on a series of phonatory function tasks carried out during continuous karaoke singing. Half of the singers were given water to drink and short duration of vocal rests at regular intervals during singing and the other half sang continuously without taking any water or rest. The subjects who were given hydration and vocal rests sang significantly longer than those who did not take any water or rest. The voice quality, as measured by perceptual and acoustic measures, and vocal function, as measured by phonetogram, did not show any significant changes during singing in the subjects who were given water and rest during the singing. However, subjects who sang continuously without drinking water and taking rests showed significant changes in the jitter measure and the highest pitch they could produce during singing. These results suggest that hydration and vocal rests are useful strategies to preserve voice function and quality during karaoke singing. This information is useful educational information for karaoke singers.

Cross‐cultural Adaptation and Validation of the Chinese Voice Handicap Index‐10

Objectives/Hypothesis: Recent developments in voice assessment propose the use of quality of life measurements. The Voice Handicap Index (VHI) is one of the most psychometrically robust and well‐studied instruments among the various instruments for measuring quality of life. Two versions of VHI (VHI‐30 and VHI‐10) have been shown to be valid instruments for distinguishing dysphonic from nondysphonic individuals and also for documenting treatment effect for dysphonic patients. The VHI has been used worldwide; however, the psychometric properties of the Chinese version of VHI remains untested. This study aimed to investigate such properties of the Chinese VHI‐30 and VHI‐10 in the Hong Kong Chinese population.

Equal Appearing Interval and Visual Analogue Scaling of Perceptual Roughness and Breathiness.

One of the factors that affects the reliability of perceptual voice evaluation is the rating scale. Equal‐appearing interval (EAI) and visual analogue (VA) scales are the two most common scales used and have attracted much attention in recent studies of perceptual voice evaluation. Available findings are contradictory, with one study finding the EAI scale to be more desirable while an earlier study showed equivocal results. The objective of the present study was to compare the reliability of using an 11‐point EAI scale and a VA scale, each of 10 cm long, for perceptual voice quality evaluation. Thirty listeners with no prior experience in perceptual voice evaluation were asked to rate the breathy and rough qualities of 28 voice samples. The results showed that the listeners demonstrated a significantly higher intra‐rater agreement and lower inter‐rater variability in rating the two perceptual voice qualities using the EAI scale, when compared to the VA scale. However, listeners tend to show more bias in using certain points on the EAI scale than on the VA scale. In addition, a linear relationship was found between the EAI and VA ratings, suggesting the psychoperceptual characteristics of breathy and rough qualities could be captured equally well by the EAI and VA scales. Since the ease of use of the rating scale is an important consideration in clinical situations, the 11‐point, 10 cm long EAI scale is therefore more preferable, although not necessarily more superior, than the VA scale for evaluating breathy and rough qualities.

Suitability of Acoustic Perturbation Measures in Analysing Periodic and Nearly Periodic Voice Signals

In recent years, acoustic perturbation measurement has gained clinical and research popularity due to the ease of availability of commercial acoustic analysing software packages in the market. However, because the measurement itself depends critically on the accuracy of frequency tracking from the voice signal, researchers argue that perturbation measures are not suitable for analysing dysphonic voice samples, which are aperiodic in nature. This study compares the fundamental frequency, relative amplitude perturbation, shimmer percent and noise-to-harmonic ratio between a group of dysphonic and non-dysphonic subjects. One hundred and twelve dysphonic subjects (93 females and 19 males) and 41 non-dysphonic subjects (35 females and 6 males) participated in the study. All the 153 voice samples were categorized into type I (periodic or nearly periodic), type II (signals with subharmonic frequencies that approach the fundamental frequency) and type III (aperiodic) signals. Only the type I (periodic and nearly periodic) voice signals were acoustically analysed for perturbation measures. Results revealed that the dysphonic female group presented significantly lower fundamental frequency, significantly higher relative amplitude perturbation and shimmer percent values than the non-dysphonic female group. However, none of these three perturbation measures were able to differentiate between male dysphonic and male non-dysphonic subjects. The noise-to-harmonic ratio failed to differentiate between the dysphonic and non-dysphonic voices for both gender groups. These results question the sensitivity of acoustic perturbation measures in detecting dysphonia and suggest that contemporary acoustic perturbation measures are not suitable for analysing dysphonic voice signals, which are even nearly periodic.

Effectiveness of functional communication therapy by volunteers for people with aphasia following stroke

The aim of this study was to develop and evaluate a scripted modular intervention programme called Speaking Out. Speaking Out is administered by trained volunteers in the home and focuses on the everyday communicative activities of aphasic stroke patients. The experimental design used repeated measures to examine the effect of counterbalanced treatments across individual subjects and across two matched groups. One group improved significantly on the Western Aphasia Battery (WAB) after the Speaking Out programme but there were no significant differences on any of the functional communication measures. Some change to health status scales was however found. There was a significant difference on both the WAB and the ASHA Functional Assessment of Communication Skills (ASHA FACS) for the other group following the Speaking Out programme. They also demonstrated some positive changes on the health status scales following the programme. There were more significant differences on intragroup comparisons than intergroup comparisons. For group 2, the ASHA FACS and the SF-36 showed significant differences between the Speaking Out programme and the recreational programme or no treatment at all. It was concluded that long standing aphasic speakers may benefit from a 10 week functional communication therapy programme delivered by trained volunteers.

Reliability and confidence in using a paired comparison paradigm in perceptual voice quality evaluation.

One of the ways to improve the reliability in perceptual voice quality rating is to provide listeners with external anchors. A paired comparison matching paradigm using synthesized Cantonese voice stimuli that covered a range of rough and breathy qualities were used to investigate the rating reliability. Twenty‐five speech pathology students rated the severity of roughness and breathiness of natural pathological voice samples using two paradigms: an eight‐point anchored matching (paired comparison) paradigm and an eight‐point non‐anchored equal‐appearing‐interval (EAI) scale paradigm. The listeners also rated their confidence in judging each testing stimulus on a seven‐point EAI scale. The results showed that the paired comparison method specifically improved the inter‐rater reliability in rating male rough stimuli and mildly dysphonic female stimuli. The intra‐rater agreement and confidence ratings remained similar across the two rating paradigms. These results suggest that the paired comparison paradigm may be used as an alternative perceptual voice quality evaluation tool.

Reliability and Applicability of Aerodynamic Measures in Dysphonia Assessment.

Aerodynamic measures are frequently used to analyse and document pathological voices. Some normative data are available for speakers from the English‐speaking population. However, no data are available yet for Chinese speakers despite the fact that they are one of the largest populations in the world. The high variability of aerodynamic measures between and within subjects raises the issue of reliability and usefulness of this procedure in discriminating between normal and pathological voices. This study aimed to investigate the use of mean airflow rate and sub‐glottal pressure in predicting normal and pathological voices. It also aimed to determine whether a higher number of repeated airflow measures would provide a better representation of the normative data in distinguishing normal from abnormal voices. The study provided a small set of preliminary normative data for Chinese speakers. Aerodynamic measures were collected from 56 Cantonese female adults using a Kay Elemetrics Aerophone II. The results showed that the accuracy in predicting a voice to be dysphonic or normal using aerodynamic measures was as high as 91.1%. The accuracy was found to improve when the number of measurements for each aerodynamic parameter was increased from three to five. The overlapping of data between the dysphonic and non‐dysphonic groups, however, suggests that the aerodynamic measures should be used as an adjunct to assessment of voice disorders rather than as a diagnostic tool alone.

Scaling voice activity limitation and participation restriction in dysphonic individuals.

The purpose of this study was to determine the most appropriate scaling procedure for evaluating voice activity limitation (AL) and voice participation restriction (PR). In a randomly counterbalanced design, 32 dysphonic individuals rated their self-perceived extents of voice AL and PR using two scaling procedures [equal-appearing interval (EAI) scaling and visual analogue (VA) scaling]. Results revealed that test-retest reliabilities were similar for the two scaling procedures. The overall extents of voice AL and PR obtained from the two scaling procedures were similar. Moreover, the significant linear relationships obtained between the EAI and VA data of voice AL and PR suggest both dimensions as metathetic in nature. Therefore, either EAI or VA scaling procedure would be considered as appropriate for rating voice AL and PR. However, the relative ease to use by consumers favours the choice of EAI over VA scaling procedure for evaluating voice AL and PR.