Acceptable Noise Level in Unilateral Ménière’s Disease

Background and Aim: Noise tolerance and performance in noisy environments are influential factors of hearing aid use in people with hearing loss. One of the causes of hearing loss is Meniere’s disease (MD), which affects speech perception in noise. Acceptable noise level (ANL) is a test that measures the maximum tolerated background noise level (BNL) while listening to the running speech. Since the effect of MD on ANL needs further study, the present study aims to examine the ANL test results in people with unilateral MD, and compare the results between the two ears. Methods: This cross sectional study conducted on 33 individuals with unilateral MD (21 females and 12 males) aged 32–60 years who had the disease for at least one year, who participated in this study. Their most comfortable level (MCL), BNL, and ANL in both ears were then evaluated. Results: The mean MCL and BNL were significantly different between the two ears, where they were higher in the affected ear than in the contralateral ear. There was also a significant difference in the ANL results between the two ears. In the affected ear, a statistically significant relationship was reported between the ANL and the average hearing thresholds at frequencies of 250, 500, and 1000 Hz. Conclusion: MD affects the ANL in the affected ear and causes a deterioration in its level and speech perception in noise.

The Role of the Medial Olivocochlear Reflex in Acceptable Noise Level in Adults

Background The acceptable noise level (ANL) is a measurement used to quantify how much noise a person is willing to accept while listening to speech. ANL has been used to predict success with hearing aid use. However, physiological correlates of the ANL are poorly understood. One potential physiological correlate is the medial olivocochlear reflex (MOCR), which decreases the output of the cochlea and is thereby expected to increase noise tolerance. Purpose This study investigates the relationship between contralateral activation of the MOCR and tolerance of background noise. Research Design This study recruited 22 young adult participants with normal hearing. ANL was measured using the Arizona Travelogue recording under headphones presented at the most comfortable level (MCL) with and without multitalker babble noise. The MOCR strength was evaluated in all participants by measuring the cochlear microphonic (CM) with and without 40 dB sound pressure level contralateral broadband noise (CBBN). Data Analysis The CM observed in response to a 500-Hz tone was measured with and without CBBN, and changes in response to fast Fourier transform amplitude at 500 Hz were used as an indicator of the MOCR effect. The ANL was calculated by subtracting the maximum acceptable background noise level from the MCL. Participants were divided into two groups based on their ANL: low-ANL (ANL < 7 dB) and moderate-ANL (ANL ≥ 7 dB). An independent samples t-test was used to compare CM enhancement between low-ANL and moderate-ANL groups. Additionally, Pearson's correlation was used to investigate the relationship between the ANL and the MOCR effect on the CM. Results The results indicated that presentation of CBBN increased the CM amplitude, consistent with eliciting the MOCR. Participants in the low-ANL group had significantly larger CM enhancement than moderate-ANL participants. The results further revealed a significant correlation between the ANL and the MOCR effect on the CM. Conclusion This study suggests that a stronger MOCR, as assessed using CM enhancement, is associated with greater noise tolerance. This research provides a possible objective measure to predict background tolerance in patients and adds to our understanding about the MOCR function in humans.

The effects of noise exposure and work-related fatigue on the acceptable noise level test in normal-hearing people

Background and Aim: The acceptable noise level (ANL) assesses the noise that a person can tolerate during a running speech. Although it is a strong test, it has not yet become popular in clinical practice. One of the reasons is its contradictory results. Since it is a psychoacoustic test, psychological factors can affect its output. Investigation of these factors can provide more accurate results. This study aims to investigate the effects of noise and work-related fatigue on the ANL in normal-hearing people. Methods: Participants were the male workers in the administration (n = 26) and production (n = 26) departments of an automotive manufacturing industry in Iran. They were evaluated before and after leaving the workplace in order to determine the effects of noise exposure, fatigue as well as their simultaneous effects on the ANL. Results: In both groups, the ANL showed a significant increase after work compared to its level before work, and the background noise level (BNL) was significantly decreased. There was no significant difference in the BNL between administration and production groups before work. The most comfortable level (MCL) showed no significant increase. Moreover, the MCL changes were not significantly different in the production group compared to administration group, but the BNL and ANL changes were significantly higher. Conclusion: Noise exposure and work-related fatigue affect the ANL. During the ANL test, earlier exposure to noise and the amount of fatigue should be controlled. Keywords: Exposure to noise; fatigue; acceptable noise level

Acceptable Noise Levels Determined by Traditional and Self-Assessed Methods

Background Many apps have been developed for users to screen their hearing in their own home. The purpose of this study was to investigate the validity and efficiency of a self-assessed acceptable noise level (ANL) in comparison to the traditional ANL measurements. Research Design A within-subject repeated measures research design was utilized. Data Collection and Analysis Sixty-two adults with normal hearing were recruited from Auburn University and the surrounding community. ANLs were measured utilizing the traditional measurement as well as the self-assessed ANL via the Unitron uHear app. Results Within-subject repeated measures of variance revealed no significant differences between traditional ANL measurements and self-assessed ANL measurements. Significant differences were found for time required for testing in each condition, revealing self-assessed testing to be significantly faster. Conclusion The self-assessed ANL measurement via the Unitron uHear app is a valid and efficient measurement of ANL in adults with normal hearing.

Acceptable Noise Level Stability Over a One-Year Period of Time

Background The acceptable noise level (ANL) is a measure of willingness to listen to speech in the presence of background noise and is thought to be related to success with amplification. To date, ANLs have only been assessed over short periods of time, including within a session and over a 3-week and 3-month time period. ANL stability over longer periods of time has not been assessed. Purpose The purpose was to examine the stability of ANL over a 1-year time period. Research Design A repeated-measures, longitudinal study was completed. Study Sample Thirty young adults with normal hearing served as participants. The participants were tested at two different sites. Data Collection and Analysis Two trials of most comfortable listening levels (MCLs), background noise levels (BNLs), and ANLs were assessed for each participant during three experimental sessions: at 0 months, 6 months, and 1 year. Results Two-way repeated-measures analysis of variances revealed no significant change in MCLs, BNLs, or ANLs within a session or over a 1-year time period. These results indicate that ANLs remain stable for 1 year in listeners with normal hearing. Conclusions The finding that the ANL is stable over a longer period of time supports the theory that the ANL is an inherent trait of the listener and mediated at in the central auditory nervous system.

Assessment of acceptable noise level in unilateral hearing aid users

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

Application of Acceptable Noise Level to Confirm Fitting Strategy for Bone-Anchored Hearing Aid

Since there is no standardized fitting procedure for bone-anchored hearing aid (BAHA) patients, many clinics have failed to perform their successful fitting. The present case study tried to identify whether acceptable noise level (ANL) was clinically applied as one of fitting procedures for the BAHA users. Four hearing-impaired adults with BAHA (3 female and 1 male) who had a period of hearing deprivation for at least 8 years and the BAHA experience of more than 1 year participated. They conducted ANL in their unaided and aided BAHA conditions after being familiar with the ANL instruction. Also, the subjects responded to a self-report of Korean version of Profile of Hearing Aid Benefit (K-PHAB) to subjectively check amount of satisfaction with BAHA. Compared to the unaided condition, two out of four BAHA users showed a decreased ANL in the aided condition whereas the other users had a slightly increased ANL. Regardless, their levels were examined within the permissible range except for one subject. Their K-PHAB scores were similar to the ANL results in the aided condition. Although measured ANLs were slightly differed from the users, the current results suggest that ANL might be a tool to measure individual’s inherent value when the BAHA fitting being appropriated while also supported by K-PHAB scores. In the following study, we need to confirm a typical pattern of many BAHA users with longitudinal measures of ANL.

The Effect of Digital Noise Reduction on Annoyance and Speech Perception in Low and High Acceptable Noise Level Groups

Introduction Studies have reported that although speech perception in noise was unaltered with and without digital noise reduction (DNR), the annoyance toward noise measured by acceptable noise level (ANL) was significantly improved by DNR with the range between 2.5 and 4.5 dB. It is unclear whether a similar improvement would be observed in those individuals who have an ANL ≥ 14 dB (predictive of poor hearing aid user) often rejects their aid because of annoyance toward noise. Objectives (a) To determine the effect of activation of DNR on the improvement in the aided ANL from low- and high-ANL groups; and (b) to predict the change in ANL when DNR was activated. Method Ten bilateral mild to severe sloping sensorineural hearing loss (SNHL) participants in each of the low- and high-ANL groups were involved. These participants were bilaterally fitted with receiver in canal (RIC) hearing aids (Oticon, Smorum, Egedal, Denmark) with a DNR processor. Both SNR-50% (Signal to noise ratio (in dB) required to achieve 50 % speech recognition) and ANL were assessed in DNR-on and DNR-off listening conditions. Results Digital noise reduction has no effect on SNR-50 in each group. The annoyance level was significantly reduced in the DNR-on than DNR-off condition in the low-ANL group. In the high-ANL group, a strong negative correlation was observed between the ANL in DNR off and a change in ANL after DNR was employed in the hearing aid (benefit). The benefit of DNR on annoyance can be effectively predicted by baseline-aided ANL by linear regression. Conclusion Digital noise reduction reduced the annoyance level in the high-ANL group, and the amount of improvement was related to the baseline-aided ANL value.