Background and Aim: It is well known that hearing aid fitting is an effective approach to improve the communication ability of hearingimpaired people. In the past, most of the hearing aids were fitted unilaterally rather than bilaterally. Whereas the unilateral hearing aid fitting improves verbal communication partially, it causes late-onset auditory deprivation. The main aim of this study is to investigate the ANL for each ear among the users with unilateral hearing aid experience. Methods: A total of 23 participants were recruited (14 females, 9 males). The mean age was 74.65 years (ranged from 41 to 83). All subjects had bilateral symmetric sensorineural hearing loss. The most comfortable level (MCL), Background Noise Level (BNL), and acceptable noise level (ANL) were measured for ear with amplification experience and ear without experience. Results: MCL, BNL and ANL in the aided ear was 82.22, 73.48 and 8.74 respectively, in addition in the unaided ear the results for MCL, BNL and ANL was 81.78, 72.13 and 9.65 respectively. Comparing the mean values of MCL, BNL and ANL between two ears showed no significant difference. Conclusion: There was not any difference for BNL and ANL measures Keywords: Bilateral hearing loss; acceptable noise level; late onset auditory deprivation; Hearing aid