Tympanometric norms in Chinese children aged 6 to 7 years and tympanometric patterns in Chinese neonates prior to hospitaldischarge

by Au, Wai-yin

(Uncorrected OCR) Abstract of dissertation entitled Tympanometric Norms in Chinese Children Aged 6 to 7 Years and

Tympanometric Patterns in Chinese Neonates Prior to Hospital Discharge submitted by

Au Wai Yin Joyce

for the degree of Master of Science in Audiology at the University of Hong Kong

in May 2002

The aims of the present study were to establish tympanometric norms for Chinese children aged 6 to 7 years, and to explore the patterns of 226 Hz, 678 Hz, and 1000 Hz probe tone tympanometry in Chinese neonates prior to hospital discharge.

Conventional tympanometry was recorded in 110 (56 males and 54 females) normal hearing children recruited from 3 different local primary schools in Hong Kong. Normative values for static admittance (Peak V), equivalent ear canal volume 01 ec), tympanometric width (TW), and tympanometric peak pressure (TPP) were computed. Findings were compared with those of Wan (2000) and Margolis and Heller (1987) in order to investigate the age and racial effects on the four tympanometric variables. Results indicated that the mean Peak Y, Vec, and TPP values of Chinese children were significantly smaller than those of Chinese adults, whereas the mean TW value of Chinese children was significantly larger than that of Chinese adults. Results also indicated that males had significantly larger Vec value

vii

than females in Chinese children. Findings revealed Chinese children had smaller Peak Y and larger TW values than did Caucasian children despite the age differences, which seemed to suggest racial differences on Peak Y and Vec values.

Thirty-eight (19 males and 19 females) non high-risk neonates prior to hospital discharge were tested with the 226 Hz, 678 Hz, and 1000 Hz tympanometry. More than half of the tested ears yielded double-peaked tympanograms in conventional tympanometry, thus neither Jerger (1970) classification nor conventional normative data were applicable for further analysis. High probe tone tympanograms with "clear peak", "small peak", and "peaked with abnormal positive MEP" were recorded in neonates who passed Transient-evoked Otoacoustic Emission (TEOAE) screening using Sutton, Gleadle, and Rowe (1996) classification system. Yet, middle ear problem could not be ruled out for ears being classified as having "small peak", or "peaked with abnormal positive middle ear pressure". Problems encountered in testing neonates as well as future research directions were discussed.

viii