Clinical applications of transiently evoked otoacoustic emissions in the pediatric population

Our objectives were 1) to determine whether transiently evoked otoacoustic emissions (TEOAEs) are affected by the status of the tympanic membrane (TM) and middle ear (ME) as determined by clinical examinations and tympanogram s; 2) to determine the efficacy of TEOAEs in detecting hearing loss; and 3) to determine the relative effects of the ME status and hearing loss on TEO AEs. In a prospective observational study in a tertiary care children's hos pital, 89 patients (169 cars: 9 ears eliminated from analyses) were examine d by 2 attending pediatric otolaryngologists for otologic conditions and un derwent audiologic evaluations including TEOAEs from August 1994 through Ma y 1995. The main outcome measures were presence or absence of TEOAE whole r eproducibility (WR) and reproducibility (R) at 2 kHz. Statistical analyses showed that of the 8 ME and TM conditions evaluated (normal. TM perforation , pressure equalization [PE] tube, TM retraction, tympanosclerosis, TM atro phy. ME effusion, surgery other than PE tube insertion). only the presence of ME effusion and normal examination findings had a significant effect on the results of WR and R at 2 kHz. Of the 6 different types of tympanograms evaluated (A, B, C, AD, As, B with large volume), type A. B, and C tympanog rams had a significant effect on WR and types A and B had a significant eff ect on R at 2 kWz. Hearing losses greater than or equal to 25 dB hearing le vel (I-IL) at any of the 5 frequencies (0.25, 0.5, 1, 2, and 1 kHz) were we ll predicted by the absence of WR and R at kHz. When clinical examination a nd impedance data were evaluated simultaneously with hearing status, hearin g status had a greater effect on WR and R at 2 kHz. We conclude that type B and C tympanograms and the presence of ME effusion (which reflect abnormal ME status) have an adverse effect on TEOAEs. However. the presence of hear ing loss is the most significant predictor of TEOAE results. The TEOAE WR a nd R at 2 kHz are effective in identifying patients with normal hearing and with hearing losses greater than or equal to 25 dB HL.