Acceptance of noise growth patterns in hearing aid users.

PURPOSE: To examine whether the effects of speech presentation level on acceptance of noise could differentiate full-time, part-time, and nonusers of hearing aids and whether these effects could predict hearing aid use. METHOD: Participants were separated into 3 groups on the basis of hearing aid use: (a) full-time use, (b) part-time use, or (c) nonuse. Acceptable noise levels (ANLs) were measured conventionally and at 8 fixed presentation levels. The effects of presentation level on ANL were determined by calculating global ANL (ANL averaged across presentation level) and ANL growth (slope of the ANL function). RESULTS: Global ANLs were smaller for full-time users than for part-time users and nonusers; however, global ANLs were not different for part-time users and nonusers. ANL growth differentiated full-time users from nonusers only. Conventional ANL predicted hearing aid use with 68% accuracy. Compared with conventional ANL, the accuracy of the prediction for global ANL and ANL growth decreased, and the accuracy of the prediction at presentation levels of 65 to 75 dB HL was maintained. CONCLUSIONS: Global ANL differentiated the hearing aid groups in the same manner as conventional ANL. The effects of presentation level on acceptance of noise did not considerably increase the accuracy of the prediction compared with conventional ANL. Clinical applications are discussed.     

Comparison of speech perception in background noise with acceptance of background noise in aided and unaided conditions.

Background noise is a significant factor influencing hearing-aid satisfaction and is a major reason for rejection of hearing aids. Attempts have been made by previous researchers to relate the use of hearing aids to speech perception in noise (SPIN), with an expectation of improved speech perception followed by an increased acceptance of hearing aids. Unfortunately, SPIN was not related to hearing-aid use or satisfaction. A new measure of listener reaction to background noise has been proposed. The acceptable noise level (ANL), expressed in decibels, is defined as a difference between the most comfortable listening level for speech and the highest background noise level that is acceptable when listening to and following a story. The ANL measure assumes that speech understanding in noise may not be as important as is the willingness to listen in the presence of noise. It has been established that people who accept background noise have smaller ANLs and tend to be "good" users of hearing aids. Conversely, people who cannot accept background noise have larger ANLs and may only use hearing aids occasionally or reject them altogether. Because this is a new measure, it was important to determine the reliability of the ANL over time with and without hearing aids, to determine the effect of acclimatization to hearing aids, and to compare the ANL to well-established measures such as speech perception scores collected with the SPIN test. Results from 50 listeners indicate that for both good and occasional hearing aid users, the ANL is comparable in reliability to the SPIN test and that both measures do not change with acclimatization. The ANLs and SPIN scores are unrelated. Although the SPIN scores improve with amplification, the ANLs are unaffected by amplification, suggesting that the ANL is inherent to an individual and can be established prior to hearing aid fitting as a possible predictor of hearing-aid use.     

Toleration of background noises: relationship with patterns of hearing aid use by elderly persons

One of the frequently quoted reasons for the rejection of hearing aids is amplification of background noise. The relationship between hearing aid use and toleration of background noise was assessed. Four groups of elderly subjects (at least 65 years old) and one group of young subjects with normal hearing participated in the study. Each group consisted of 15 subjects. The young subjects and elderly subjects in one group with relatively good hearing were tested for comparison with the hearing-impaired subjects. Elderly subjects in the three remaining groups had acquired hearing losses and had been fitted with hearing aids. The subjects were assigned to three groups on the basis of hearing aid use: full-time users, part-time users, and nonusers. The amount of background noise tolerated when listening to speech was tested. The speech stimulus was a story read by a woman and set at an individually chosen most comfortable level. The maskers were a babble of voices, speech-spectrum noise, traffic noise, music, and the noise of a pneumatic drill. There was a significant interaction between groups and noises. The full-time users tolerated significantly higher levels of music and speech-spectrum noise than part-time users and nonusers. In addition, the full-time users, but not the part-time users, assessed themselves as less handicapped in everyday functions when they wore hearing aids than when they did not wear their hearing aids.     

Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

Abstract Objective: The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA). Design: ANL was measured in three conditions in both ears at two test sessions. Subjects completed the IOI-HA and the ANL questionnaire. Study sample: Sixty-three Danish hearing-aid users; fifty-seven subjects were full time users and 6 were part time/non users of hearing aids according to the ANL questionnaire. Results: ANLs were similar to results with American English speech material. The coefficient of repeatability (CR) was 6.5-8.8 dB. IOI-HA scores were not associated to ANL. Conclusions: Danish and non-semantic ANL versions yield results similar to the American English version. The magnitude of the CR indicates that ANL with Danish and non-semantic speech materials is not suitable for prediction of individual patterns of future hearing-aid use or evaluation of individual benefit from hearing-aid features. The ANL with Danish and non-semantic speech materials is not related to IOI-HA outcome.     

Advantages of Binaural Amplification to Acceptable Noise Level of Directional Hearing Aid Users

Objectives

The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals'' demographic information were investigated.

Methods

Fourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners'' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing.

Results

The results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals'' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds.

Conclusion

Binaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners'' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for clinical counseling of binaural hearing aid candidates or unsuccessful users.     

Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

Abstract

Objective: The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users’ ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA). Design: ANL was measured in three conditions in both ears at two test sessions. Subjects completed the IOI-HA and the ANL questionnaire. Study sample: Sixty-three Danish hearing-aid users; fifty-seven subjects were full time users and 6 were part time/non users of hearing aids according to the ANL questionnaire. Results: ANLs were similar to results with American English speech material. The coefficient of repeatability (CR) was 6.5–8.8 dB. IOI-HA scores were not associated to ANL. Conclusions: Danish and non-semantic ANL versions yield results similar to the American English version. The magnitude of the CR indicates that ANL with Danish and non-semantic speech materials is not suitable for prediction of individual patterns of future hearing-aid use or evaluation of individual benefit from hearing-aid features. The ANL with Danish and non-semantic speech materials is not related to IOI-HA outcome.     

Acceptable noise level as a measure of directional hearing aid benefit

An acceptable noise level (ANL) procedure for measuring hearing aid directional benefit was compared with masked speech reception threshold (SRT) and front-to-back ratio (FBR) procedures. ANL is the difference between the most comfortable listening level and the maximum accepted background noise level while listening to speech. Forty adult subjects wearing their own binaural hearing aids were evaluated in omnidirectional and directional modes. The subjects were fitted with a variety of hearing aids by clinical audiologists, independent of the study. For each procedure, speech and noise were presented through loudspeakers located at 0 degrees and 180 degrees azimuth, respectively. Mean ANL (3.5 dB), SRT (3.7 dB), and FBR (2.9 dB) directional benefits were not significantly different. The ANL and masked SRT benefits were significantly correlated. The ANL appears to be a quick, clinician/user friendly procedure for measuring hearing aid directional benefit.     

The effects of speech presentation level on acceptance of noise in listeners with normal and impaired hearing.

PURPOSE: To compare the effects of speech presentation level on acceptance of noise in listeners with normal and impaired hearing. METHOD: Participants were listeners with normal (n = 24) and impaired (n = 46) hearing who were matched for conventional acceptable noise level (ANL). ANL was then measured at 8 fixed speech presentation levels (40, 45, 50, 55, 60, 65, 70, and 75 dB HL) to determine if global ANL (i.e., ANL averaged across speech presentation levels) or ANL growth (i.e., the slope of the ANL function) varied between groups. RESULTS: The effects of speech presentation level on acceptance of noise were evaluated using global ANLs and ANL growth. Results showed global ANL and ANL growth were not significantly different for listeners with normal and impaired hearing, and neither ANL measure was related to pure-tone average for listeners with impaired hearing. Additionally, conventional ANLs were significantly correlated with both global ANLs and ANL growth for all listeners. CONCLUSION: These results indicate that the effects of speech presentation level on acceptance of noise are not related to hearing sensitivity. These results further indicate that a listener's conventional ANL was related to his or her global ANL and ANL growth.     

Speech recognition measures with noise suppression hearing aids using a single-subject experimental design

Research aimed at quantifying the benefits a hearing aid user might expect from noise suppression hearing aids purported to improve hearing in the presence of background noise have yielded widely varying results. We suggest this may in part be due to the inappropriate use of experimental approaches based on group design and inferential statistical analysis. Included in this paper is our rationale for employing a single-subject experimental design to investigate subject performance with two commercially available hearing-aid noise suppression systems. Preliminary results with two subjects indicate that both the Siemens Automatic Signal Processing (ASP) and Zeta Noise Blocker (ZNB) noise suppression systems markedly improve listener scores on the low predictability sentence material of the SPIN Test. We conclude these two noise suppression systems may improve performance as the listening situation becomes contextually more difficult, and that single-subject experimental designs could be a valuable addition to applied behavioral research with hearing aids.     

Full time directional versus user selectable microphone modes in hearing aids

OBJECTIVE: The purpose of this experiment was to systematically examine hearing aid benefit as measured by speech recognition and self-assessment methods across omnidirectional and directional hearing aid modes. These data were used to compare directional benefit as measured by speech recognition in the laboratory to hearing aid wearer's perceptions of benefit in everyday environments across full-time directional, full-time omnidirectional, and user selectable directional fittings. Identification of possible listening situations that resulted in different self reported hearing aid benefit as a function of microphone type was a secondary objective of this experiment. DESIGN: Fifteen adults with symmetrical, sloping sensorineural hearing loss were fitted bilaterally with in-the-ear (ITE) directional hearing aids. Measures of hearing aid benefit included the Profile of Hearing Aid Benefit (PHAB), the Connected Sentence Test (CST), the Hearing in Noise Test (HINT), and a daily use log. Additionally, two new subscales were developed for administration with the PHAB. These subscales were developed to specifically address situations in which directional hearing aids may provide different degrees of benefit than omnidirectional hearing aids. Participants completed these measures in three conditions: omnidirectional only (O), directional only with low-frequency gain compensation (D), and user-selectable directional/omnidirectional (DO). RESULTS: Results from the speech intelligibility in noise testing indicated significantly more hearing aid benefit in directional modes than omnidirectional. PHAB results indicated more benefit on the background noise subscale (BN) in the DO condition than in the O condition; however, this directional advantage was not present for the D condition. Although the reliability of the newly proposed subscales is as yet unknown, the data were interpreted as revealing a directional advantage in situations where the signal of interest was in front of the participant and a directional disadvantage in situations where the signal of interest was behind the listener or localization was required. CONCLUSIONS: Laboratory directional benefit is reflected in self-assessment measures that focus on listening in noise when the sound source of interest is in front of the listener. The use of a directional hearing aid mode; however, may have either a positive, a neutral, or a negative impact on hearing aid benefit measured in noisy situations, depending on the specific listening situation.     

The influence of listener's gender on the acceptance of background noise

The acceptance of background noise can be assessed by having participants select the maximum background noise level (BNL) to which they are willing to listen while following speech at their most comfortable listening level (MCL). The difference between the selected BNL and MCL is the acceptable noise level (ANL). Preliminary investigations have revealed large between-participant ANL differences that are not related to age, hearing status, preference for background noise, or uncomfortable listening level. This study investigated listener's gender as a possible factor contributing to these between-participant differences. Comfortable listening levels for speech and accepted levels of speech-babble background noise were obtained binaurally, via the sound field, from 50 (25 male, 25 female) young, acoustically naive adults with normal hearing sensitivity. Results indicate that, although males had higher comfortable listening levels and accepted higher levels of background noise than females, ANL values were not different between males and females.     

Relationship between acceptable noise level and the abbreviated profile of hearing aid benefit.

PURPOSE: This study investigated the relationship between acceptable noise levels (ANLs) and the Abbreviated Profile of Hearing Aid Benefit (APHAB; R. M. Cox & G. C. Alexander, 1995). This study further examined the APHAB's ability to predict hearing aid use. METHOD: ANL and APHAB data were collected for 191 listeners with impaired hearing, separated into 3 groups based on hearing aid use: full-time, part-time, or nonuse. RESULTS: Results demonstrated ANLs were not correlated with APHAB scores. Results further demonstrated 2 of the 4 APHAB subscales (Ease of Communication [EC] and Background Noise [BN]) predicted hearing aid success with 60% accuracy, which is 25% poorer than that observed using the ANL alone. When combining the ANL with the EC and BN subscales, accuracy of the prediction increased to 91%. Lastly, 3 of the 4 APHAB subscales (EC, BN, and Reverberation) enhanced the present prediction of hearing aid use for patients with mid-range ANLs. CONCLUSIONS: These results indicate that ANLs and APHAB scores provide unique information regarding hearing aid use. These results further indicate that the prediction can be enhanced by administering both the ANL and the EC and BN APHAB subscales. Lastly, some of the ambiguity of the prediction of hearing aid use for listeners with mid-range ANLs may be eliminated.     

Contribution of high-frequency information to the acceptance of background noise in listeners with normal and impaired hearing

PURPOSE: To determine whether information beyond 2.0 kHz affected the acceptance of background noise in listeners with normal and/or impaired hearing. METHOD: Speech stimuli (Arizona Travelogue) and multitalker babble were low-pass filtered at cutoff frequencies of 2.0, 4.0, and 6.0 kHz and presented using an adaptive paradigm to determine the most comfortable level (MCL) and acceptable noise level (ANL) for 4 experimental conditions (unfiltered, 2.0, 4.0, and 6.0 kHz) for each listener. RESULTS: MCL for listening to speech in quiet was significantly increased when the speech stimuli were low-pass filtered at 2.0 kHz relative to the unfiltered and 6.0-kHz conditions. Acceptance of background noise was significantly poorer when the speech and noise stimuli were low-pass filtered at 2.0 kHz relative to the 6.0-kHz condition. Listeners with impaired hearing sensitivity had significantly greater MCL values than listeners with normal hearing, but ANL values were not significantly affected by the hearing sensitivity of the listener. CONCLUSIONS: Information beyond 2.0 kHz significantly affected MCL and ANL values in both listeners with normal hearing and impaired hearing; however, effects for both the MCL and ANL measurements were small and may not be significant clinically.     

可接受噪声级测试在单、双耳佩戴助听器效果评估中的应用

目的 通过比较双侧中重度听力损失患者在单、双耳助听下的可接受噪声级(acceptable noise level,ANL),探讨ANL对助听器验配及预测助听效果的作用.方法 选取15例双侧中重度听力损失患者,分别测得双耳未助听、左耳助听、右耳助听和双耳助听状态下的最舒适响度级(most comfortable levels,MCL)、最大背景噪声级(background noise level,BNL),并计算得到ANL值(ANL=MCL-BNL),对结果进行统计学分析.结果 15例受试者双耳未助听、左耳助听、右耳助听及双耳助听四种状态下测得的ANL值分别为18.87±5.26、12.60±2.47、12.00±2.90、5.13±1.25 dB S/N;MCL值分别为80.40±9.28、63.73±5.15、62.27±5.36、61.80±6.05 dB HL;BNL值分别为61.67±6.14、51.13±3.94、50.27±4.50、56.67±5.16 dB HL;左耳助听与右耳助听下的ANL值差异无统计学意义(P>0.05);单、双耳助听下与未助听的ANL值差异均具有统计学意义(P<0.05);双耳助听状态下ANL值显著低于单耳助听(P<0.05).结论 ANL值较低耳更利于助听器验配,佩戴助听器能有效提高听障患者对噪声的接受能力,并且双耳佩戴助听器的效果明显优于单耳.     

New perspectives on assessing amplification effects

Clinicians have long been aware of the range of performance variability with hearing aids. Despite improvements in technology, there remain many instances of well-selected and appropriately fitted hearing aids whereby the user reports minimal improvement in speech understanding. This review presents a multistage framework for understanding how a hearing aid affects performance. Six stages are considered: (1) acoustic content of the signal, (2) modification of the signal by the hearing aid, (3) interaction between sound at the output of the hearing aid and the listener's ear, (4) integrity of the auditory system, (5) coding of available acoustic cues by the listener's auditory system, and (6) correct identification of the speech sound. Within this framework, this review describes methodology and research on 2 new assessment techniques: acoustic analysis of speech measured at the output of the hearing aid and auditory evoked potentials recorded while the listener wears hearing aids. Acoustic analysis topics include the relationship between conventional probe microphone tests and probe microphone measurements using speech, appropriate procedures for such tests, and assessment of signal-processing effects on speech acoustics and recognition. Auditory evoked potential topics include an overview of physiologic measures of speech processing and the effect of hearing loss and hearing aids on cortical auditory evoked potential measurements in response to speech. Finally, the clinical utility of these procedures is discussed.     

An objective measure for selecting microphone modes in OMNI/DIR hearing aid circuits

OBJECTIVES: Studies have shown that listener preferences for omnidirectional (OMNI) or directional (DIR) processing in hearing aids depend largely on the characteristics of the listening environment, including the relative locations of the listener, signal sources, and noise sources; and whether reverberation is present. Many modern hearing aids incorporate algorithms to switch automatically between microphone modes based on an analysis of the acoustic environment. Little work has been done, however, to evaluate these devices with respect to user preferences, or to compare the outputs of different signal processing algorithms directly to make informed choices between the different microphone modes. This study describes a strategy for automatically switching between DIR and OMNI microphone modes based on a direct comparison between acoustic speech signals processed by DIR and OMNI algorithms in the same listening environment. In addition, data are shown regarding how a decision to choose one microphone mode over another might change as a function of speech to noise ratio (SNR) and spatial orientation of the listener. DESIGN: Speech and noise signals were presented at a variety of SNR's and in different spatial orientations relative to a listener's head. Monaural recordings, made in both OMNI and DIR microphone processing modes, were analyzed using a model of auditory processing that highlights the spectral and temporal dynamics of speech. Differences between OMNI and DIR processing were expressed in terms of a modified spectrotemporal modulation index (mSTMI) developed specifically for this hearing aid application. Differences in mSTMI values were compared with intelligibility measures and user preference judgments made under the same listening conditions. RESULTS: A comparison between the results of the mSTMI analyses and behavioral data (intelligibility and preference judgments) showed excellent agreement, especially in stationary noise backgrounds. In addition, the mSTMI was found to be sensitive to changes in SNR as well as spatial orientation of the listener relative to signal and noise sources. Subsequent mSTMI analyses on hearing aid recordings obtained from real-life environments with more than one talker and modulated noise backgrounds also showed promise for predicting the preferred microphone setting in varied and complex listening environments.     

Speech understanding in quiet and noise,with and without hearing aids

Speech recognition and cognitive functions important for speech understanding were evaluated by objective measures and by scores of perceived effort, with and without hearing aids. The tests were performed in silence, and with background conditions of speech spectrum random noise and ordinary speech. One young and one elderly group of twelve hearing-impaired subjects each participated. Hearing aid use improved speech recognition in silence (7 dB) and in the condition with speech as background (2.5 dB S/N), but did not change the perceived effort scores. In the cognitive tests no hearing aid benefit was seen in objective measures, while there was an effect of hearing aid use in scores of perceived effort, subjects reported less effort. There were no age effects on hearing aid benefit. In conclusion, hearing aid use may result in reduced effort in listening tasks that is not associated with improvement in objective scores.     

Speech understanding in quiet and noise, with and without hearing aids

Speech recognition and cognitive functions important for speech understanding were evaluated by objective measures and by scores of perceived effort, with and without hearing aids. The tests were performed in silence, and with background conditions of speech spectrum random noise and ordinary speech. One young and one elderly group of twelve hearing-impaired subjects each participated. Hearing aid use improved speech recognition in silence (7 dB) and in the condition with speech as background (2.5 dB S/N), but did not change the perceived effort scores. In the cognitive tests no hearing aid benefit was seen in objective measures, while there was an effect of hearing aid use in scores of perceived effort, subjects reported less effort. There were no age effects on hearing aid benefit. In conclusion, hearing aid use may result in reduced effort in listening tasks that is not associated with improvement in objective scores.     

Amplification with digital noise reduction and the perception of annoying and aversive sounds

Hearing aid users report difficulties using their hearing aids in noisy environments. Problems include understanding speech, loudness discomfort, and annoyance with background noise. Digital noise reduction algorithms have been promoted as a method to solve speech understanding and comfort in noise problems. Research has failed to find improved speech understanding in noise. Little is known about how digital noise reduction affects noise annoyance and aversiveness. The goals of this investigation were to determine how a specific digital noise reduction system affects hearing aid users' perception of noise annoyance and aversiveness and to compare their perceptions to those of normal-hearing listeners. Ratings of noise annoyance and of aversiveness were obtained from 49 participants with moderate sensorineural hearing loss before fitting and after 3 weeks of hearing aid use. Findings were compared to measures obtained from normal-hearing listeners. Perceived annoyance and aversiveness increased with amplification. Annoyance and aversiveness with the hearing aid approximated normal perception. The results of this investigation suggest the need for counseling patients about realistic expectations related to annoyance and aversiveness of sounds at the time of hearing aid fitting.     

The effect of speech presentation level on acceptance of background noise in listeners with normal hearing

A method has been established to measure the maximum acceptable background noise level (BNL) for a listener, while listening to speech at the most comfortable listening level (MCL). The acceptable noise level (ANL) is the difference between BNL and MCL. In the present study, the ANL procedure was used to measure acceptance of noise, first, in the presence of speech at MCL and, then, for speech presented at much lower and higher levels in listeners with normal hearing. This study used the term ANL to describe the results obtained at MCL and also at other speech presentation levels. The mean ANL at MCL was 15.5 dB, which is comparable to results obtained by previous investigators. ANL increases systematically with speech presentation level. Mean ANLs ranged from 10.6 dB when speech was presented at 20 dB HL to 24.6 dB when speech was presented at 76 dB HL. The results indicated that the acceptance of noise depends significantly on speech presentation level.