Objectives: Otoacoustic emissions are signals that originate from the cochlea, measuring them can be considered an objective method in the assessment of auditory function. In our study we wanted to examine their efficiency among normal audiological exams.
Materials and methods: We examined 14 workers exposed to continuous aircraft noise. They underwent ENT examination, metric eardrum test, hearing test tone audiometry system powered by 1 dB, spontaneous otoacoustic emissions and evoked otoacoustic emissions. For inclusion in the study the patients had to show bilateral normoacusia at the audiometry.
Results: The variation of the audiometric tracks was statistically significant (p <0.05) at a frequency of 4 kHz. As to SNR parameter (relationship between sound/noise) we noticed a tendency of the transient-evoked otoacustic emission (TEOAE) to shift their spectral content, in particular a decrease in the high frequency response and on the other hand an increase at low frequencies. A similar trend for shifting in latency of otoacoustic waves emissions after exposure to chronic noise.
Conclusions: The measurement of evoked transient otoacoustic emissions is well tolerated by the workers and provides objective results, so it is a more effective and objective method then the tone audiometry.