The role of otoacoustic emissions in audiological assessment of children with suspected hearing loss

Introduction: Otoacoustic emissions are sounds that result from energy generated in the cochlea. The otoacoustic emissions test helps to confirm outer hair cell function. Aim: The objective of the study was to evaluate the expression of distortion product otoacoustic emissions in children with suspected hearing loss. Method: This retrospective study included 115 children, 65 males (56.5%) and 50 females (43.5%), aged 0 to 14 years (mean age of 6.9±3.5 years), examined during the period from January 2017 to March 2021. The audiological assessment included Distortion product otoacoustic emissions test, tympanometry, and pure-tone audiometry in children older than 4 years. Distortion product otoacoustic emissions were recorded in the form of DP- gram elicited by two primary tone stimuli L1=65 dB SPL and L2=55 dB SPL. Levels of the 2f1-f2 distortion product otoacoustic emissions were registered at frequencies from 1000 Hz to 8000 Hz at four points per octave. For statistical data analysis we used Chi-square test with level of significance p<.05. Results: From the total of 81 children with tonal audiogram, 13 children (16%) had sensorineural hearing loss with mean distortion product otoacoustic emissions amplitude -7.4 dB SPL, and 68 children (84%) had normal hearing with mean DPOAE amplitude 9.9 dB SPL. In children without tonal audiogram, distortion product otoacoustic emissions were present in 23 children (67.6%) at control examination after absence during middle ear pathology and 9 children (26.5%) at first examination. Otoacoustic emissions were absent in 2 children (5.9%) without middle ear pathology. They were mostly absent at frequency of 4000 Hz (p=.036). Conclusion: The otoacoustic emissions test is good cross-check for pure- tone audiometry. In children with sensorineural hearing loss, the otoacoustic emissions are absent in the range of hearing loss. In young children not cooperative for pure-tone audiometry, expression of otoacoustic emissions after previous absence during middle ear pathology would indicate that there is no coexistent sensorineural hearing loss