Most Comfortable Listening Level Research Articles

The Impact of Transducer Selection on the Acceptable Noise Level

The aim of this study was to assess the impact of transducer (loudspeaker, supra-aural headphones, and insert earphones) selection on the acceptable noise level (ANL). Thirty young adults with normal hearing who reported difficulty with background noise served as participants. A repeated-measures experimental design was employed. Most comfortable listening level (MCL) and background noise level (BNL) were measured for all participants using three transducers (loudspeaker, supra-aural headphones, and insert earphones). ANL was computed as the difference between the mean MCL and the mean BNL. Analytical statistics revealed that ANL did not differ due to the transducer used. However, there were statistically significant differences found for MCL and BNL across transducers. Results of this study indicate that ANL is not vulnerable to the selection of transducer and that ANLs can be compared across transducer types. Researchers should cautiously interpret findings across studies when discussing the base measures of MCL and BNL as these may be influenced slightly by transducer selection.

Improving Acceptance of Background Noise with Sound Enrichment.

Acceptance of background noise serves as a means to predict likelihood of hearing aid success. Individuals that are able to accept background noise are more likely to be successful with hearing aids. The aim of the study was to assess the impact of sound enrichment on the acceptable noise level (ANL). Nineteen young adult participants served as listeners. Participants were randomly assigned to the experimental or control group. An experimental design with random assignment to experimental or control group was used. One group used sound enrichment procedures for 2 weeks, whereas the other group served as a control group. Sound enrichment procedures required that participants add low-level background sound to any quiet environment encountered during the study. Most comfortable listening level (MCL) and background noise level (BNL) were measured at three sessions, each 1 week apart (baseline, after 1 week of treatment, and after 2 weeks of treatment). Analytical statistics revealed that ANL improved for the sound enrichment group but remained the same for the control group. For both groups, there was no significant change in MCL across sessions. However, for the experimental group, BNL improved (increased) over the 2-week period while using sound enrichment. Results of this study indicate that ANL can be improved with the use of sound enrichment procedures over a 2-week period. Future work should examine the use of sound enrichment procedures for older adults with hearing loss.

Improving Acceptance of Background Noise with Sound Enrichment

Background: Acceptance of background noise serves as a means to predict likelihood of hearing aidsuccess. Individuals that are able to accept background noise are more likely to be successful with hearingaids.Purpose: The aim of the study was to assess the impact of sound enrichment on the acceptable noiselevel (ANL).Study Sample: Nineteen young adult participants served as listeners. Participants were randomlyassigned to the experimental or control group.Research Design: An experimental design with random assignment to experimental or control groupwas used.Data Collection and Analysis: One group used sound enrichment procedures for 2 weeks, whereas theother group served as a control group. Sound enrichment procedures required that participants add lowlevelbackground sound to any quiet environment encountered during the study. Most comfortable listeninglevel (MCL) and background noise level (BNL) were measured at three sessions, each 1 weekapart (baseline, after 1 week of treatment, and after 2 weeks of treatment).Results: Analytical statistics revealed that ANL improved for the sound enrichment group but remainedthe same for the control group. For both groups, there was no significant change in MCL across sessions.However, for the experimental group, BNL improved (increased) over the 2-week period while usingsound enrichment.Conclusions: Results of this study indicate that ANL can be improved with the use of sound enrichmentprocedures over a 2-week period. Future work should examine the use of sound enrichment proceduresfor older adults with hearing loss.

Vibrant Soundbridge can improve the most comfortable listening level in sensorineural hearing loss: Our experience with 61 patients.

In auditory rehabilitation, the most comfortable listening level (MCL) is important because the conversation partners of patients with hearing impairment are often individuals with normal hearing. Thus, normalizing MCL can help patients with hearing loss to reduce the communication handicap with individuals with normal hearing. While active middle ear implants demonstrate comparable performance with conventional hearing aids (HA) with regard to functional hearing gain and speech intelligibility, little is known about the effect of middle ear implants on the MCL. Therefore, we evaluated the MCL of active middle-ear implants compared with that of conventional HA in patients with moderate and moderate-to-severe sensorineural hearing loss (SNHL). We found that the Vibrant Soundbridge (VSB) active middle-ear implant had a pure-tone threshold similar to conventional HA. However, the MCL in VSB-aided conditions was significantly lower (by ~10 dB) than for HA-aided conditions. In addition, the significant improvement in MCL was attributable to robust amplifications at 1 kHz and 2 kHz compared with conventional HA. VSB implantation nearly normalized MCL for patients with SNHL. In terms of normalizing MCL, VSB implantation is a good choice for hearing rehabilitation in patients with SNHL. This article is protected by copyright. All rights reserved.

Intertester Reliability of the Acceptable Noise Level

The acceptable noise level (ANL) serves to accurately predict the listener's likelihood of success with amplification. It has been proposed as a pre-hearing aid fitting protocol for hearing aid selection and counseling purposes. The ANL is a subjective measure of the listener's ability to accept background noise. Measurement of ANL relies on the tester and listener to follow the instructions set forth. To date, no research has explored the reliability of ANL as measured across clinicians or testers. To examine the intertester reliability of ANL. A descriptive quasi-experimental reliability study was completed. ANL was measured for one group of listeners by three testers. Three participants served as testers. Each tester was familiar with basic audiometry. Twenty-five young adults with normal hearing served as listeners. Each tester was stationed in a laboratory with the needed equipment. Listeners were instructed to report to these laboratories in a random order provided by the experimenters. The testers assessed most comfortable listening level (MCL) and background noise level (BNL) for all 25 listeners. Intraclass correlation coefficients were significant and revealed that MCL, BNL, and ANLs are reliable across testers. Additionally, one-way ANOVAs for MCL, BNL, and ANL were not significant. These findings indicate that MCL, BNL, and ANL do not differ significantly when measured by different testers. If the ANL instruction set is accurately followed, ANL can be reliably measured across testers, laboratories, and clinics. Intertester reliability of ANL allows for comparison across ANLs measured by different individuals. Findings of the present study indicate that tester reliability can be ruled out as a factor contributing to the disparity of mean ANLs reported in the literature.

Most Comfortable Listening Levels, Background Noise Levels, and Acceptable Noise Levels for Children and Adults with Normal Hearing

For adults the acceptable noise level (ANL) has been shown to be a strong predictor of hearing aid success. ANL is calculated as the difference between most comfortable listening level (MCL) and background noise level (BNL). No studies have made direct comparisons of these measures between adults and children. To evaluate and compare MCLs, BNLs, and ANLs in children and young adults. A cross-sectional design was used in this study. Two groups (children and adults) were tested for each dependent variable. MCLs and BNLs were measured for each participant, and ANLs were computed from these two measurements. The participants were 34 children (8-10 yr) and 34 young adults (19-29 yr) with normal hearing. Significant main effects were found for MCLs and BNLs. There was no main effect for ANLs. MCLs and BNLs were significantly lower for the children than for the adults. These results suggest that while ANLs are unchanged from childhood to adulthood, there appears to be a developmental change in MCLs and BNLs. These findings have implications for the use of ANLs in the pediatric population.

Effects of reverberation on acceptable noise level measurements in younger and older adults

Acceptable noise level (ANL) test materials were digitally modified to create five reverberant conditions by applying different values of reverberation time (RT) to a non-reverberant condition (RT = 0, 0.4, 0.7, 1.2, and 2 s). Two groups of 12 subjects participated: younger individuals (22–29 years, M = 24.3) and older adults (50–69 years, M = 57.5). Mean hearing threshold levels (250 to 8000 Hz) for both groups were 30 dB HL or better. Most comfortable listening level (MCL) and background noise level (BNL) measurements were completed in each reverberant condition, and from these measurements, ANLs were calculated. Significant main effects for age and reverberation were not found for ANL or MCL. These results suggest that reverberation does not affect the amount of background noise individuals are willing to accept, or the level of speech individuals choose as the MCL. These results can be used by clinical audiologists to counsel patients regarding the use of communication strategies. Additionally, these results can be used to support previous findings that ANL is not related to the intelligibility of the speech signal.SumarioSe modificaron digitalmente materiales de prueba de niveles aceptables de ruido (ANL) para crear cinco condiciones de reverberación, aplicando diferentes valores de tiempo de reverberación (RT) a una condición no reverberante (RT = 0, 0.4, 0.7, 1.2, y 2 s). Participaron dos grupos de 12 sujetos: jóvenes (22–29 años, M = 24.3) y adultos mayores (50–69 años, M = 57.5). La media de los umbrales auditivos (250 a 8000 Hz) en ambos grupos fue de 30 dB HL o mejor. El mejor nivel confortable de audición (MCL) y las mediciones del nivel de ruido de fondo (BNL) se completaron en cada condición de reverberación y de estas mediciones, se calcularon los ANL. No se encontraron efectos significativos por edad y reverberación para el ANL o el MCL. Estos resultados sugieren que la reverberación no afecta la cantidad de ruido de fondo que los individuos stán dispuestos a aceptar ni el nivel de lenguaje que seleccionan como el MCL. Estos resultados pueden ser usados por los audiólogos clínicos para aconsejar a los pacientes en relación con el uso de estrategias comunicativas. Adicionalmente, pueden usarse para apoyar hallazgos previos en cuanto a que los ANL no se relacionan con la inteligibilidad de las señales del habla.

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.

Physiologic correlates to background noise acceptance

Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

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 acceptance of background noise and hearing aid use

Background noise produces complaints among hearing-aid users, however speech-perception-in-noise does not predict hearing-aid use. It is possible that hearing-aid users are complaining about the presence of background noise and not about speech perception. To test this possibility, acceptance of background noise is being investigated as a predictor of hearing-aid use. Acceptance of background noise is determined by having subjects select their most comfortable listening level (MCL) for a story. Next, speech-babble is added and the subjects select the maximum background noise level (BNL) which is acceptable while listening to and following the story. The difference between the MCL and the BNL is the acceptable noise level (ANL), all in dB. ANLs are being compared with hearing-aid use, subjective impressions of benefit (APHAB), speech perception in background noise (SPIN) scores, and audiometric data. Individuals who accept higher levels of background noise are more successful users than individuals who accept less background noise. Mean ANLs are 7.3 dB for full-time users (N=21), 12.6 dB for part-time users (N=44), and 13.8 dB for rejecters (N=17). ANLs are not related to APHAB, SPIN, or audiometric data. Results for about 120 subjects will be reported. [Work supported by NIDCD (NIH) RO1 DC 05018.]

Comparison of acceptance of background noise and speech reception threshold in quantifying the hearing aid directivity benefit

Hearing aid directivity benefit was compared as improvement in acceptance of background noise and speech reception threshold (SRT). Forty adult subjects were tested wearing binaural hearing aids in omnidirectional and directional listening conditions. Acceptance of background noise was determined by having subjects select their most comfortable listening level (MCL) for a story delivered from a loudspeaker (0). Next, speech babble was added (180) and the subjects selected the maximum background noise level (BNL) which was acceptable while listening to and following the story. The MCL minus the BNL yielded the acceptable noise level (ANL), all in dB. The difference between the ANL for the omni-directional and directional conditions is the directivity benefit. The SRT was determined by delivering spondaic words (0) at the subjects MCL. Next, speech babble was delivered (180) and adjusted until the subject could repeat 50% of the spondees. The difference between the SRT for the omni-directional and directional conditions is the directivity benefit. Mean directional benefit, ANL=3.50 dB and SRT=3.60 dB, were not significantly different. The individual ANLs and SRTs were significantly correlated (r=−0.36, p=0.002). The ANL procedure appears to be a viable tool for quantifying hearing aid directivity benefit. [Work supported by NIDCD (NIH) 3 RO1 DC 05018-01S1.]

Most comfortable listening level as a function of age.

The Most Comfortable Listening Level (MCLL) was determined for a running speech signal in a sample of 799 subjects, ranging in age from 17 to 92 years of age. The MCLL increased monotonically with increasing chronological age, in a non-linear relationship. Before the age of 40 MCLL increased approximately one-third of a dB per annum, while after the age of 65 MCLL increased by more than one half dB per year. Over the 75 year age range MCLL rose by 34 dB. Confirming earlier reports, MCLL was also found to be related to hearing sensitivity. Some implications for the design of sound systems are suggested.

Vowel temporal masking of pitch recognition for consonant‐like noise bursts by normal‐ and impaired‐hearing listeners

Impaired‐ and normal‐hearing subjects (Ss) identified the pitch of either a low‐, mid‐, or high‐frequency noise burst in a recognition‐masking task with a two‐formant vowel masker which preceded and/or followed the noise burst. F1 of the vowel was at 700 Hz and F2 at 1100 Hz. The three noise bursts were bands of flat‐spectrum noise: 500–1500 Hz, 1500–4000 Hz, or 4000–6000 Hz. Forward‐, backward‐, and combined‐forward‐and‐backward‐masking conditions were tested with a 10 ms Δt. The vowel was presented at most comfortable listening level (MCL) for the impaired and at 90 dB SPL for the normal‐hearing Ss: the noise bursts were presented at 10 dB SL. Pitch recognition of the noise bursts was affected least in the backward‐masking condition and was poorest in the combined‐forward‐and‐backward‐masking condition. In the combined masking condition nearly all Ss showed some masking of pitch recognition for one or more of the noise bursts. Masking occurred most often for the low‐frequency burst and least often for the high‐frequency burst. Generally, release from masking was seen when Δt was lengthened to 100 ms.

Most comfortable listening level presentation versus maximum discrimination for word discrimination material.

The purpose of the present study was to determine if most comfortable listening level (MCL) presentation of word discrimination material would yield maximum discrimination for normal and sensorineural hearing loss subjects. The results of the study indicated that normally hearing listeners do obtain maximum discrimination at MCL, while presentation of word discrimination material at MCL to sensorineural hearing loss listeners does not yield maximum discrimination. Further examination of the results would also contraindicate the use of any other method which incorporates single or dual presentation levels as a means of determining maximum discrimination for the sensorineural hearing loss listener.

Most comfortable listening for the loudness and intelligibility of speech.

The effect of instructional set upon most comfortable listening (MCL) was investigated among normal listeners. MCL level and range were determined (method of limits) in relation to listening for comfortable speech loudness versus comfortable speech intelligibility. The results indicate that instructional set does influence listener performance. the mean MCL level for comfortable speech intelligibility was significantly higher (4.96 dB) than the mean level for comfortable speech loudness; the mean MCL range for comfortable speech intelligibility was higher by 7.33 dB and wider by 7.10 dB than the mean range for speech loudness. Ascending stimulus presentation obtained comparable MCL levels for both listening conditions, whereas descending presentation obtained a mean MCL level almost 10 dB higher for comfortable speech intelligibility than for comfortable speech loudness. Males achieved slightly higher MCL levels than did females for both loudness (4.32 dB) and intelligibility (4.96 dB) criteria. It was concluded that the nature of the instructional set be taken into account when interpreting comfortable listening measures.

Use of Sensation Level in Measurements of Loudness and of Temporary Threshold Shifts

The hypothesis that equal sensation levels (SL) of stimulation give rise to equivalent loudnesses in normal observers is disproven by showing that recruitment often occurs near threshold even in normal ears. Since neither constant sound pressure levels (SPL) nor constant SL's including 0 dB SL (threshold itself), can be assumed to produce equal loudness, it is suggested that observers be equated at the most comfortable listening level (MCL).