Prevalence and management outcomes of tonic tensor tympani syndrome in an ENT audiology tinnitus clinic in Singapore.

OBJECTIVE: Tonic tensor tympani syndrome is found in a subset of tinnitus patients who experience intra-aural and peri-aural symptoms, in addition to their tinnitus, in the absence of clinically detectable pathology. As the syndrome has not been widely reported, this study aims to determine its prevalence and evaluate the effectiveness of current management. METHODS: The tinnitus management clinic records of patients over the past six years were assessed to identify tonic tensor tympani syndrome patients and track their progress based on patient-reported Tinnitus Handicap Index scores. Patients with reversible ear pathology and temporomandibular joint disorder were excluded. RESULTS: It was found that 13 per cent of the tinnitus management patients fulfilled the criteria for tonic tensor tympani syndrome and 94 per cent of those who returned for follow up showed an improvement in their Tinnitus Handicap Index grades. CONCLUSION: This study suggests that tonic tensor tympani syndrome is a significant problem among tinnitus patients and current tinnitus management strategies contribute effectively to helping such patients habituate to their symptoms.

Development of SC-10: A psychometrically equivalent Singapore Mandarin disyllabic word list for clinical speech audiometry use.

OBJECTIVE: The aim of this study is to develop and evaluate a set of psychometrically equivalent disyllabic wordlist (SC-10) in Singapore Mandarin for clinical use. STUDY DESIGN: A preliminary set of 1000 words were obtained from a dictionary of frequently used words by Singapore students. Ten native judges rate the familiarity level of each word. This is followed by a face-to-face public survey to rank the shortlisted word set from most to least familiar. The final 108 disyllabic words were recorded by a native female talker. 20 normal hearing subjects were used to obtain the percentage of correct word recognition at 24 intensity levels (-10 dB HL to 26 dB HL in 2 dB increment). Psychometric function slopes were calculated for each word. 100 words were eventually chosen and assigned into ten 10-word lists based on a psychometric balancing protocol. Minor digital adjustments were made to the intensity of each wordlist to improve their auditory homogeneity.The developed SC-10 wordlists were validated by a separate group of 25 normal hearing subjects. Test-retest reliability was carried out on 20 out of 25 participants at the selected intensity levels (SRT-5, SRT, SRT+5). RESULTS: The calculated regression slopes in the psychometric functions for the ten lists are between 8.0 and 9.8%/dB. Single factor ANOVA analysis showed no significant difference in both the mean intensity required to obtain 50% recognition score (f = 0.109, df = 9, p = 0.999) and the slopes of the psychometric functions (f = 0.078, df = 9, p = 0.999) between the ten word lists. List validation on 25 normal hearing participants (PTA = 11.0 dB HL, SD = 4.3) showed a mean speech recognition threshold (SRT) of 9.3 dB HL (SD = 3.5)and regression slope of 8.395%/dB. Quadratic regression analysis showed a positive correlation (r 2 = 0.923) between presentation level and word recognition score (WRS). The difference between PTA and SRT of each subject all fall within the clinically acceptable difference of 10 dB HL. Test-retest reliability, carried out on 20 subjects at three levels (SRT-5, SRT, and SRT+5 dB), showed no significance difference between word recognition score when the same participant is tested again at the same intensity level using a different wordlist. CONCLUSION: All in all, it shows that the SC-10 speech materials are valid for clinical use for Mandarin speech audiometry in Singapore.

Relationship between leisure noise exposure and otoacoustic emissions in a young Asian population.

OBJECTIVE: This study compared the otoacoustic emissions amplitudes of Asian youths at risk of leisure noise exposure through the use of portable music players with their less exposed counterparts. DESIGN: A listening habit survey was conducted. Subjects were divided into two groups for analysis. A subject was placed within the high risk group if he/she reported listening to music at near maximum volume and had a physical measurement of his/her preferred listening level recorded at > 85 dBA. DPOAE and TEOAE levels were measured and compared between the two groups. STUDY SAMPLE: A total of 1928 students from a tertiary educational institution in Singapore. RESULTS: TEOAE levels were found to be significantly lower in the high risk group at 4 kHz. DPOAE levels were also found to be significantly depressed in the high risk group at 1, 2, 3, and 4 kHz with the largest mean difference at 4 kHz. A four-way ANOVA carried out for OAE amplitudes using gender, ear laterality, risk profile, and years of usage as independent factors also showed that risk profile was a significant factor in determining the OAE amplitude at 4 kHz. CONCLUSION: We have demonstrated that both DPAOE and TEOAE values are diminished in the Asian subjects at high risk for noise exposure.

The music listening preferences and habits of youths in Singapore and its relation to leisure noise-induced hearing loss.

INTRODUCTION: Noise-induced hearing loss (NIHL) is a preventable condition, and much has been done to protect workers from it. However, thus far, little attention has been given to leisure NIHL. The purpose of this study is to determine the possible music listening preferences and habits among young people in Singapore that may put them at risk of developing leisure NIHL. METHODS: In our study, the proportion of participants exposed to > 85 dBA for eight hours a day (time-weighted average) was calculated by taking into account the daily number of hours spent listening to music and by determining the average sound pressure level at which music was listened to. RESULTS: A total of 1,928 students were recruited from Temasek Polytechnic, Singapore. Of which, 16.4% of participants listened to portable music players with a time-weighted average of > 85 dBA for 8 hours. On average, we found that male students were more likely to listen to music at louder volumes than female students (p < 0.001). We also found that the Malay students in our study listened to louder music than the Chinese students (p < 0.001). CONCLUSION: We found that up to one in six young persons in Singapore is at risk of developing leisure NIHL from music delivered via earphones. As additional risks due to exposure to leisure noise from other sources was not taken into account, the extent of the problem of leisure NIHL may be even greater. There is a compelling need for an effective leisure noise prevention program among young people in Singapore.