Protective Effect of N-Acetylcysteine against Continuous Noise-Induced Hearing Loss

Background: This study aimed to determine the preventive effect of N-Acetylcysteine (NAC) against continuous noise-induced hearing loss. Materials Methods: A total of 24 adult male Wistar rats were randomly assigned into 4 groups of 6 animals: control, noise, noise and NAC, noise and saline. Animals were subjected to 102 dB (102±0.5) of continuous, 8 kHz-centered high pass white noise. For two days before to noise, one hour prior to noise for ten days in a row, and two days after noise, NAC (325 mg/kg) was intraperitoneally administered. Temporary and permanent hearing loss were assessed by pre and post noise (1, 7 and 21 days) recordings of distortion product otoacoustic emissions (DPOAEs). Results: Amplitudes was temporally reduced significantly first day post noise exposure in all groups, and all frequencies (P 0.05). The initial and subsequent recovery was more pronounced in noise-exposed animal treated with NAC compared to those received noise and saline, especially in higher frequencies (P 0.05). Noise and NAC group experienced less permanent hearing loss than noise and saline group (P 0.05). Conclusions: NAC could partially improve permanent hearing loss after noise exposure However, temporary hearing loss was not affected by NAC.