Characteristics of transient otoacoustic emissions in patients with sudden idiopathic hearing loss.

In a prospective study of 24 patients hospitalized with sudden idiopathic hearing loss syndrome (SIHLS), tonal audiometry was conducted first at an early stage after onset (Day O), again a second time (Day A, mean = 4.12 days), and again a third time (Day B, mean = 8.71 days). Transient evoked otoacoustic emissions (TEOAE) were recorded on Days O and A elicited by click stimulation. The question under investigation was whether TEOAE presence, TEOAE amplitude or peak amplitudes for the various 200-Hz-wide bands on Day O could be exploited to assess cochlear function, as indicated by pure-tone audiometry on Days A and B. The TEOAE amplitude on Day O was found to be correlated with improvement in tone threshold on Day B at 2 kHz. One significant correlation emerged between the band amplitude on Day O and the audiometric frequency improvement: on Day B between peak amplitude at 1.2 kHz and 1 kHz frequency improvement. From these results, TEOAE could theoretically be a means to assess cochlear functioning during SIHLS for 1 and 2 kHz frequencies. However, correlations are too weak to form the basis of any predictive test that could be clinically useful.