VESTIBULARFUNCTION EVALUATION IN SUBJECTS WITH NOISE INDUCED HEARING LOSS

Abstract

Although, the damaging effect of noise on hearing is confirmed in different clinical and laboratory researches, the vestibular affection by hazardous noise is still a subject of debate and in need for further researches.

This study was designed to evaluate the effect of noise on the vestibular system in subjects with NIHL and to detect any possible correlation between vestibular disorders and the degree of hearing loss.

This study was conducted at the noisy departments of Assiut university hospital including the diesel, laundry, boilers, air conditioners and the oxygen preparation unit. It included 70 subjects, 50 subjects with NIHL in the study group and 20 subjects in the control group. The equipment used included: impedancemeter (Interacoustics AZ 7), dual channel clinical audiometer (Madsen OB 822), double room sound treated booth (Industrial Acoustic Company lAC Model 160 2-A•CT), sound level meter (Bruel and Kjaer 2235) and electronystagmograph (Micromedical tech, Meta 4).

All subjects (study or control groups) were subjected to the following:

1- Complete history taking.

2- ENT examination.

3- Pure tone audiometry (both air conduction and bone conduction).

4- Speech audiometry.•

5-lmpedance audiometry including tympanometry and acoustic reflex

measurements.

6- Neurological and ophthalmological examination.

7- Electronystagmography.