Vestibular evoked myogenic potential in noise-induced hearing loss

Noise affects one's hearing as well as balance mechanism. The hearing mechanism of the noise-exposed individuals has been extensively studied. However, in view of the poor research focus on the sacculo-collic reflexes, especially in this study area, the present study was undertaken to examine the vestibular evoked myogenic potentials (VEMP) in subjects with noise-induced hearing loss (NIHL). A total of 30 subjects (55 ears) with NIHL participated in the present study within the age range of 30-40 years. VEMP recordings were done at 99 dBnHL using IHS instrument. The results indicated that as the average pure tone hearing threshold increased, the VEMP latencies were prolonged and peak to peak amplitude was reduced in NIHL subjects. Out of the 55 ears, VEMP was absent in 16 (29.0%) ears. The latency was prolonged and the peak to peak amplitude was reduced in 19 (34.6%) ears. VEMP results were normal in 20 (36.4%) ears. Therefore, VEMP was abnormal or absent in 67% of NIHL subjects in the present study. Hence it can be concluded that the possibility of vestibular dysfunction, specially the saccular pathway, is high in individuals with NIHL. VEMP, a non-invasive and user friendly procedure, can be employed in these individuals to assess sacculo-collic reflex.