Is Pattern of Acceptable Noise Level Growth for Apparently Normal Contralateral Ear Similar to Affected Ear in Unilateral Meniere’s Disease?

Abstract

Background and Aim: The Acceptance Noise Level (ANL) which determines the tolerable noise level while listening to running speech, is related to factors such as hearing loss and speech presentation level. This study aims to investigate the effect of speech presentation level on the ANL in people with unilateral Meniere’s Disease (MD) compared to the normal-hearing people.
 Methods: In this study, 33 people aged 32–60 years with unilateral MD and 38 normal-hearing people aged 20–46 years participated. The ANL growth was evaluated unilaterally at four different speech presentation levels: Most Comfortable Level (MCL), –10 dB lower than the MCL, +10 dB higher than the MCL, and a range between MCL and uncomfortable level.
 Results: In MD patients, the ANL of the affected ear was significantly different from that of the contralateral ear (p<0.010). Compared to the normal-hearing people, the pattern of ANL growth in MD patients was significantly different, but the ANL growth patterns were similar between the affected and contralateral ears.
 Conclusion: ANL and its growth pattern are different between the affected and contralateral ears of patients with unilateral MD, but are similar compared to normal-hearing people. Despite the apparently normal hearing thresholds, the performance of the contralateral ear in noise at various speech presentation levels in patients with unilateral MD seems to be similar to that of the affected ear.
 Keywords: Meniere disease; hearing loss; acceptable noise level