Wideband Tympanometry Findings in School-aged Children: Effects of Age, Gender, Ear Laterality, and Ethnicity

Objectives: Wideband tympanometry (WBT) measures middle-ear function across a range of frequencies (250 to 8000 Hz) while the ear-canal pressure is varied from +200 to -300 daPa. WBT is a suitable test to evaluate middle-ear function in children, but there is a lack of age-, ear-, gender-, or ethnicity-specific data throughout the literature. The purpose of this study was to investigate the effects of age, ear laterality, gender, and ethnicity on the WBT data retrieved from children aged 4 to 13 years determined to have normal middle-ear function. Design: Data were collected cross-sectionally from 924 children aged 4 to 13 years who passed a test battery consisting of 226-Hz tympanometry, ipsilateral acoustic stapedial reflexes, and pure-tone screening, and without significant history of middle-ear dysfunction. Participants were grouped according to their age: 4 to 6 years, 7 to 9 years, 10 to 13 years. Wideband absorbance values were extracted at 0 daPa (WBA(0)) and tympanometric peak pressure (WBA(TPP)). Results: The effects of age, frequency, and pressure (WBA(0) versus WBA(TPP)) were statistically significant. There were significant differences between WBA(0) and WBA(TPP) for all age groups such that WBA(0) had lower absorbance at low frequencies (250 to 1600 Hz) and greater absorbance at mid to high frequencies (2500 to 8000 Hz). Statistically significant effects of age were present for WBA(0) and WBA(TPP) such that absorbance generally increased with age from 250 to 1250 Hz and decreased with age from 2000 to 5000 Hz. There were no significant main effects of gender, ear, or ethnicity. Conclusions: Gender-, ear-, and ethnicity-specific clinical WBA(0) and WBA(TPP) norms are not required for diagnostic purposes; however, age-specific norms may be necessary. Age-related changes in middle-ear function were observed across WBA(0) and WBA(TPP). The data presented in this study are a suitable clinical reference for evaluating the outer- and middle-ear function of school-aged children.