The Effects of Noise Reduction Technologies on the Acceptance of Background Noise

2013 ◽  
Vol 24 (08) ◽  
pp. 649-659 ◽  
Author(s):  
Kristy Jones Lowery ◽  
Patrick N. Plyler
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Background Noise ◽  
Negative Effects ◽  
Directional Microphones ◽  
Repeated Measures Design ◽  
Noise Type ◽  
Data Collection And Analysis ◽  
Speech Spectrum

Background: Directional microphones (D-Mics) and digital noise reduction (DNR) algorithms are used in hearing aids to reduce the negative effects of background noise on performance. Directional microphones attenuate sounds arriving from anywhere other than the front of the listener while DNR attenuates sounds with physical characteristics of noise. Although both noise reduction technologies are currently available in hearing aids, it is unclear if the use of these technologies in isolation or together affects acceptance of noise and/or preference for the end user when used in various types of background noise. Purpose: The purpose of the research was to determine the effects of D-Mic, DNR, or the combination of D-Mic and DNR on acceptance of noise and preference when listening in various types of background noise. Research Design: An experimental study in which subjects were exposed to a repeated measures design was utilized. Study Sample: Thirty adult listeners with mild sloping to moderately severe sensorineural hearing loss participated (mean age 67 yr). Data Collection and Analysis: Acceptable noise levels (ANLs) were obtained using no noise reduction technologies, D-Mic only, DNR only, and the combination of the two technologies (Combo) for three different background noises (single-talker speech, speech-shaped noise, and multitalker babble) for each listener. In addition, preference rankings of the noise reduction technologies were obtained within each background noise (1 = best, 3 = worst). Results: ANL values were significantly better for each noise reduction technology than baseline; and benefit increased significantly from DNR to D-Mic to Combo. Listeners with higher (worse) baseline ANLs received more benefit from noise reduction technologies than listeners with lower (better) baseline ANLs. Neither ANL values nor ANL benefit values were significantly affected by background noise type; however, ANL benefit with D-Mic and Combo was similar when speech-like noise was present while ANL benefit was greatest for Combo when speech spectrum noise was present. Listeners preferred the hearing aid settings that resulted in the best ANL value. Conclusion: Noise reduction technologies improved ANL for each noise type, and the amount of improvement was related to the baseline ANL value. Improving an ANL with noise reduction technologies is noticeable to listeners, at least when examined in this laboratory setting, and listeners prefer noise reduction technologies that improved their ability to accept noise.

scholarly journals Sentence Recognition in Noise and Perceived Benefit of Noise Reduction on the Receiver and Transmitter Sides of a BICROS Hearing Aid

2013 ◽  
Vol 24 (10) ◽  
pp. 980-991 ◽  
Author(s):  
Kristi Oeding ◽  
Michael Valente
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Directional Microphones ◽  
Sentence Recognition ◽  
Clinically Significant ◽  
The Impact

Background: In the past, bilateral contralateral routing of signals (BICROS) amplification incorporated omnidirectional microphones on the transmitter and receiver sides and some models utilized noise reduction (NR) on the receiver side. Little research has examined the performance of BICROS amplification in background noise. However, previous studies examining contralateral routing of signals (CROS) amplification have reported that the presence of background noise on the transmitter side negatively affected speech recognition. Recently, NR was introduced as a feature on the receiver and transmitter sides of BICROS amplification, which has the potential to decrease the impact of noise on the wanted speech signal by decreasing unwanted noise directed to the transmitter side. Purpose: The primary goal of this study was to examine differences in the reception threshold for sentences (RTS in dB) using the Hearing in Noise Test (HINT) in a diffuse listening environment between unaided and three aided BICROS conditions (no NR, mild NR, and maximum NR) in the Tandem 16 BICROS. A secondary goal was to examine real-world subjective impressions of the Tandem 16 BICROS compared to unaided. Research Design: A randomized block repeated measures single blind design was used to assess differences between no NR, mild NR, and maximum NR listening conditions. Study Sample: Twenty-one adult participants with asymmetric sensorineural hearing loss (ASNHL) and experience with BICROS amplification were recruited from Washington University in St. Louis School of Medicine. Data Collection and Analysis: Participants were fit with the National Acoustic Laboratories’ Nonlinear version 1 prescriptive target (NAL-NL1) with the Tandem 16 BICROS at the initial visit and then verified using real-ear insertion gain (REIG) measures. Participants acclimatized to the Tandem 16 BICROS for 4 wk before returning for final testing. Participants were tested utilizing HINT sentences examining differences in RTS between unaided and three aided listening conditions. Subjective benefit was determined via the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire between the Tandem 16 BICROS and unaided. A repeated measures analysis of variance (ANOVA) was utilized to analyze the results of the HINT and APHAB. Results: Results revealed no significant differences in the RTS between unaided, no NR, mild NR, and maximum NR. Subjective impressions using the APHAB revealed statistically and clinically significant benefit with the Tandem 16 BICROS compared to unaided for the Ease of Communication (EC), Background Noise (BN), and Reverberation (RV) subscales. Conclusions: The RTS was not significantly different between unaided, no NR, mild NR, and maximum NR. None of the three aided listening conditions were significantly different from unaided performance as has been reported for previous studies examining CROS hearing aids. Further, based on comments from participants and previous research studies with conventional hearing aids, manufacturers of BICROS amplification should consider incorporating directional microphones and independent volume controls on the receiver and transmitter sides to potentially provide further improvement in signal-to-noise ratio (SNR) for patients with ASNHL.

Effects of a Transient Noise Reduction Algorithm on Speech Understanding, Subjective Preference, and Preferred Gain

2013 ◽  
Vol 24 (09) ◽  
pp. 845-858 ◽  
Author(s):  
Petri Korhonen ◽  
Francis Kuk ◽  
Chi Lau ◽  
Denise Keenan ◽  
Jennifer Schumacher ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Speech Intelligibility ◽  
Repeated Measures Design ◽  
Subjective Preference ◽  
Listening Environments ◽  
Speech Identification ◽  
Noise Reduction Algorithm ◽  
Phoneme Identification

Background: Today's compression hearing aids with noise reduction systems may not manage transient noises effectively because of the short duration of these sounds compared to the onset times of the compressors and/or noise reduction algorithms. Purpose: The current study was designed to evaluate the effect of a transient noise reduction (TNR) algorithm on listening comfort, speech intelligibility in quiet, and preferred wearer gain in the presence of transients. Research Design: A single-blinded, repeated-measures design was used. Study Sample: Thirteen experienced hearing aid users with bilaterally symmetrical (≤7.5 dB) sensorineural hearing loss participated in the study. Results: Speech identification in quiet (no transient noise) was identical between the TNR On and the TNR Off conditions. The participants showed subjective preference for the TNR algorithm when “comfortable listening” was used as the criterion. Participants preferred less gain than the default prescription in the presence of transient noise sounds. However, the preferred gain was 2.9 dB higher when the TNR was activated than when it was deactivated. This translated to 12.1% improvement in phoneme identification over the TNR Off condition for soft speech. Conclusions: This study demonstrated that the use of the TNR algorithm would not negatively affect speech identification. The results also suggested that this algorithm may improve listening comfort in the presence of transient noise sounds and ensure consistent use of prescribed gain. Such an algorithm may ensure more consistent audibility across listening environments.

Using the Repeat-Recall Test to Examine Factors Affecting Context Use

2021 ◽  
Author(s):  
Francis Kuk ◽  
Christopher Slugocki ◽  
Petri Korhonen
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Speech Processing ◽  
Repeated Measures ◽  
Recall Test ◽  
Outcome Measure ◽  
Hearing Aid ◽  
Listening Effort ◽  
Double Blind ◽  
Repeated Measures Design

Abstract Background The effect of context on speech processing has been studied using different speech materials and response criteria. The Repeat-Recall Test (RRT) evaluates listener performance using high context (HC) and low context (LC) sentences; this may offer another platform for studying context use (CU). Objective This article aims to evaluate if the RRT may be used to study how different signal-to-noise ratios (SNRs), hearing aid technologies (directional microphone and noise reduction), and listener working memory capacities (WMCs) interact to affect CU on the different measures of the RRT. Design Double-blind, within-subject repeated measures design. Study Sample Nineteen listeners with a mild-to-moderately severe hearing loss. Data Collection The RRT was administered with participants wearing the study hearing aids under two microphone (omnidirectional vs. directional) by two noise reduction (on vs. off) conditions. Speech was presented from 0 degree at 75 dB sound pressure level and a continuous speech-shaped noise from 180 degrees at SNRs of 0, 5, 10, and 15 dB. The order of SNR and hearing aid conditions was counterbalanced across listeners. Each test condition was completed twice in two 2-hour sessions separated by 1 month. Results CU was calculated as the difference between HC and LC sentence scores for each outcome measure (i.e., repeat, recall, listening effort, and tolerable time). For all outcome measures, repeated measures analyses of variance revealed that CU was significantly affected by the SNR of the test conditions. For repeat, recall, and listening effort measures, these effects were qualified by significant two-way interactions between SNR and microphone mode. In addition, the WMC group significantly affected CU during recall and rating of listening effort, the latter of which was qualified by an interaction between the WMC group and SNR. Listener WMC affected CU on estimates of tolerable time as qualified by significant two-way interactions between SNR and microphone mode. Conclusion The study supports use of the RRT as a tool for measuring how listeners use sentence context to aid in speech processing. The degree to which context influenced scores on each outcome measure of the RRT was found to depend on complex interactions between the SNR of the listening environment, hearing aid features, and the WMC of the listeners.

scholarly journals An Integrative Evaluation of the Efficacy of a Directional Microphone and Noise-Reduction Algorithm under Realistic Signal-to-Noise Ratios

2020 ◽  
Vol 31 (04) ◽  
pp. 262-270
Author(s):  
Francis Kuk ◽  
Christopher Slugocki ◽  
Petri Korhonen
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Signal To Noise Ratio ◽  
Working Memory Capacity ◽  
Moderate Degree ◽  
Signal To Noise ◽  
Listening Effort ◽  
Double Blind ◽  
Repeated Measures Design

Abstract Background Many studies on the efficacy of directional microphones (DIRMs) and noise-reduction (NR) algorithms were not conducted under realistic signal-to-noise ratio (SNR) conditions. A Repeat-Recall Test (RRT) was developed previously to partially address this issue. Purpose This study evaluated whether the RRT could provide a more comprehensive understanding of the efficacy of a DIRM and NR algorithm under realistic SNRs. Possible interaction with listener working memory capacity (WMC) was assessed. Research Design This study uses a double-blind, within-subject repeated measures design. Study Sample Nineteen listeners with a moderate degree of hearing loss participated. Data Collection and Analysis The RRT was administered with participants wearing the study hearing aids (HAs) under two microphones (omnidirectional versus directional) by two NR (on versus off) conditions. Speech was presented from 0° at 75 dB SPL and a continuous noise from 180° at SNRs of 0, 5, 10, and 15 dB. The order of SNR and HA conditions was counterbalanced across listeners. Each test condition was completed twice in two 2-hour sessions separated by one month. Results The recall scores of listeners were used to group listeners into good and poor WMC groups. Analysis using linear mixed-effects models revealed significant effects of context, SNR, and microphone for all four measures (repeat, recall, listening effort, and tolerable time). NR was only significant on the listening effort scale in the DIRM mode at an SNR of 5 dB. Listeners with good WMC performed better on all measures of the RRT and benefitted more from context. Although DIRM benefitted listeners with good and poor WMC, the benefits differed by context and SNR. Conclusions The RRT confirmed the efficacy of DIRM and NR on several outcome measures under realistic SNRs. It also highlighted interactions between WMC and sentence context on feature efficacy.

An Integrative Evaluation of the Efficacy of a Directional Microphone and Noise Reduction Algorithm Under Realistic Signal-to-Noise Ratios

2019 ◽  
Author(s):  
Francis Kuk ◽  
Christopher Slugocki ◽  
Petri Korhonen
Keyword(s):  
Noise Reduction ◽  
Repeated Measures ◽  
Signal To Noise Ratio ◽  
Moderate Degree ◽  
Signal To Noise ◽  
Listening Effort ◽  
Double Blind ◽  
Directional Microphones ◽  
Repeated Measures Design ◽  
Directional Microphone

Background: Many studies on the efficacy of directional microphones (DIRMs) and noise reduction (NR)algorithms were not conducted under realistic signal-to-noise ratio (SNR) conditions. A Repeat–RecallTest (RRT) was developed previously to partially address this issue.<br />Purpose: This study evaluated whether the RRT could provide a more comprehensive understanding ofthe efficacy of a DIRM and NR algorithm under realistic SNRs. Possible interaction with listener workingmemory capacity (WMC) was assessed.<br />Research Design: This study uses a double-blind, within-subject repeated measures design.<br />Study Sample: Nineteen listeners with a moderate degree of hearing loss participated.<br />Data Collection and Analysis: The RRT was administered with participants wearing the study hearingaids (HAs) under two microphones (omnidirectional versus directional) by two NR (on versus off) conditions.Speech was presented from 0° at 75 dB SPL and a continuous noise from 180° at SNRs of 0, 5,10, and 15 dB. The order of SNR and HA conditions was counterbalanced across listeners. Each testcondition was completed twice in two 2-hour sessions separated by one month.<br />Results: The recall scores of listeners were used to group listeners into good and poor WMC groups.Analysis using linear mixed-effects models revealed significant effects of context, SNR, and microphonefor all four measures (repeat, recall, listening effort, and tolerable time). NR was only significant on thelistening effort scale in the DIRM mode at an SNR of 5 dB. Listeners with good WMC performed better onall measures of the RRT and benefitted more from context. Although DIRM benefitted listeners with goodand poor WMC, the benefits differed by context and SNR.<br />Conclusions: The RRT confirmed the efficacy of DIRM and NR on several outcome measures underrealistic SNRs. It also highlighted interactions between WMC and sentence context on feature efficacy.<br />

Speech Perception in Noise Using Directional Microphones in Open-Canal Hearing Aids

2008 ◽  
Vol 19 (07) ◽  
pp. 571-578 ◽  
Author(s):  
Emily J. Klemp ◽  
Sumitrajit Dhar
Keyword(s):  
Data Collection ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Analysis Data ◽  
Impaired Hearing ◽  
Directional Microphones ◽  
Hearing In Noise ◽  
Hearing Instruments ◽  
Data Collection And Analysis ◽  
Bilateral Sensorineural Hearing Loss

Background: Individuals with impaired hearing find it difficult to understand speech in the presence of background noise—a problem addressed effectively by directional microphones. As open-canal fittings have become increasingly popular in the recent past, so has the debate about the effective directional benefit available from these devices. Purpose: This study investigates the benefit of directional microphones in two commercially available open-canal behind-the-ear hearing aids using the Hearing in Noise Test (HINT). Study Sample: Sixteen individuals, between 50 and 85 year of age, with high-frequency bilateral sensorineural hearing loss and no previous hearing aid experience participated in this study. Data Collection and Analysis: Data Collection and Analysis: Individuals were asked to repeat sentences (presented at 0° azimuth) in the presence of a diffuse-field uncorrelated broadband speech-shaped noise. HINT performance was compared across hearing instruments and conditions using a linear model with repeated measures. Results: There was a directional advantage of 2.6 dB as compared to the unaided condition. Average performance was worse in the omnidirectional mode as compared to the unaided condition. Conclusions: These results suggest that directional signal processing should not be precluded in open-canal instruments for listening in noisy environments.

The Effects of Receiver Placement on Probe Microphone, Performance, and Subjective Measures with Open Canal Hearing Instruments

2010 ◽  
Vol 21 (04) ◽  
pp. 249-266 ◽  
Author(s):  
Lynzee N. Alworth ◽  
Patrick N. Plyler ◽  
Monika Bertges Reber ◽  
Patti M. Johnstone
Keyword(s):  
Repeated Measures ◽  
Hearing Aid ◽  
Clinical Importance ◽  
Ease Of Use ◽  
Subjective Measures ◽  
Repeated Measures Design ◽  
Hearing Instruments ◽  
Data Collection And Analysis ◽  
Significant Difference ◽  
Occlusion Effect

Background: Open canal hearing instruments differ in method of sound delivery to the ear canal, distance between the microphone and the receiver, and physical size of the devices. Moreover, RITA (receiver in the aid) and RITE (receiver in the ear) hearing instruments may also differ in terms of retention and comfort as well as ease of use and care for certain individuals. What remains unclear, however, is if any or all of the abovementioned factors contribute to hearing aid outcome. Purpose: To determine the effect of receiver location on performance and/or preference of listeners using open canal hearing instruments. Research Design: An experimental study in which subjects were exposed to a repeated measures design. Study Sample: Twenty-five adult listeners with mild sloping to moderately severe sensorineural hearing loss (mean age 67 yr). Data Collection and Analysis: Participants completed two six-week trial periods for each device type. Probe microphone, objective, and subjective measures (quiet, noise) were conducted unaided and aided at the end of each trial period. Results: Occlusion effect results were not significantly different between the RITA and RITE instruments; however, frequency range was extended in the RITE instruments, resulting in significantly greater maximum gain for the RITE instruments than the RITA instruments at 4000 and 6000 Hz. Objective performance in quiet or in noise was unaffected by receiver location. Subjective measures revealed significantly greater satisfaction ratings for the RITE than for the RITA instruments. Similarly, preference in quiet and overall preference were significantly greater for the RITE than for the RITA instruments. Conclusions: Although no occlusion differences were noted between instruments, the RITE did demonstrate a significant difference in reserve gain before feedback at 4000 and 6000 Hz. Objectively; no positive benefit was noted between unaided and aided conditions on speech recognition tests. These results suggest that such testing may not be sensitive enough to determine aided benefit with open canal instruments. However, the subjective measures (Abbreviated Profile of Hearing Aid Benefit [APHAB] and subjective ratings) did indicate aided benefit for both instruments when compared to unaided. This further suggests the clinical importance of subjective measures as a way to measure aided benefit of open-fit devices.

A Comparison of Recognition Performances in Speech-Spectrum Noise by Listeners with Normal Hearing on PB-50, CID W-22, NU–6, W-1 Spondaic Words, and Monosyllabic Digits Spoken by the Same Speaker

2008 ◽  
Vol 19 (06) ◽  
pp. 496-506 ◽  
Author(s):  
Richard H. Wilson ◽  
Rachel McArdle ◽  
Heidi Roberts
Keyword(s):  
Word Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Normal Hearing ◽  
Psychometric Characteristics ◽  
Monosyllabic Word ◽  
Repeated Measures Design ◽  
Word Lists ◽  
Monosyllabic Words ◽  
Speech Spectrum

Background: So that portions of the classic Miller, Heise, and Lichten (1951) study could be replicated, new recorded versions of the words and digits were made because none of the three common monosyllabic word lists (PAL PB-50, CID W-22, and NU–6) contained the 9 monosyllabic digits (1–10, excluding 7) that were used by Miller et al. It is well established that different psychometric characteristics have been observed for different lists and even for the same materials spoken by different speakers. The decision was made to record four lists of each of the three monosyllabic word sets, the monosyllabic digits not included in the three sets of word lists, and the CID W-1 spondaic words. A professional female speaker with a General American dialect recorded the materials during four recording sessions within a 2-week interval. The recording order of the 582 words was random. Purpose: To determine—on listeners with normal hearing—the psychometric properties of the five speech materials presented in speech-spectrum noise. Research Design: A quasi-experimental, repeated-measures design was used. Study Sample: Twenty-four young adult listeners (M = 23 years) with normal pure-tone thresholds (≤20-dB HL at 250 to 8000 Hz) participated. The participants were university students who were unfamiliar with the test materials. Data Collection and Analysis: The 582 words were presented at four signal-to-noise ratios (SNRs; −7-, −2-, 3-, and 8-dB) in speech-spectrum noise fixed at 72-dB SPL. Although the main metric of interest was the 50% point on the function for each word established with the Spearman-Kärber equation (Finney, 1952), the percentage correct on each word at each SNR was evaluated. The psychometric characteristics of the PB-50, CID W-22, and NU–6 monosyllabic word lists were compared with one another, with the CID W-1 spondaic words, and with the 9 monosyllabic digits. Results: Recognition performance on the four lists within each of the three monosyllabic word materials were equivalent, ±0.4 dB. Likewise, word-recognition performance on the PB-50, W-22, and NU–6 word lists were equivalent, ±0.2 dB. The mean recognition performance at the 50% point with the 36 W-1 spondaic words was ˜6.2 dB lower than the 50% point with the monosyllabic words. Recognition performance on the monosyllabic digits was 1–2 dB better than mean performance on the monosyllabic words. Conclusions: Word-recognition performances on the three sets of materials (PB-50, CID W-22, and NU–6) were equivalent, as were the performances on the four lists that make up each of the three materials. Phonetic/phonemic balance does not appear to be an important consideration in the compilation of word-recognition lists used to evaluate the ability of listeners to understand speech.A companion paper examines the acoustic, phonetic/phonological, and lexical variables that may predict the relative ease or difficulty for which these monosyllable words were recognized in noise (McArdle and Wilson, this issue).

scholarly journals Upgrade to Nucleus® 6 in Previous Generation Cochlear™ Sound Processor Recipients

2018 ◽  
Vol 29 (09) ◽  
pp. 802-813 ◽  
Author(s):  
Allison Biever ◽  
Jan Gilden ◽  
Teresa Zwolan ◽  
Megan Mears ◽  
Anne Beiter
Keyword(s):  
Speech Perception ◽  
User Satisfaction ◽  
Repeated Measures ◽  
Background Noise ◽  
First Generation ◽  
Repeated Measures Design ◽  
Signal Processing Algorithms ◽  
Final Speech ◽  
New Algorithms ◽  
Sound Processor

AbstractThe Nucleus® 6 sound processor is now compatible with the Nucleus® 22 (CI22M)—Cochlear’s first generation cochlear implant. The Nucleus 6 offers three new signal processing algorithms that purportedly facilitate improved hearing in background noise.These studies were designed to evaluate listening performance and user satisfaction with the Nucleus 6 sound processor.The research design was a prospective, single-participant, repeated measures designA group of 80 participants implanted with various Nucleus internal implant devices (CI22M, CI24M, Freedom® CI24RE, CI422, and CI512) were recruited from a total of six North American sites.Participants had their external sound processor upgraded to the Nucleus 6 sound processor. Final speech perception testing in noise and subjective questionnaires were completed after four or 12 weeks of take-home use with the Nucleus 6.Speech perception testing in noise showed significant improvement and participants reported increased satisfaction with the Nucleus 6.These studies demonstrated the benefit of the new algorithms in the Nucleus 6 over previous generations of sound processors.

Effectiveness of Directional Microphones and Noise Reduction Schemes in Hearing Aids: A Systematic Review of the Evidence

2005 ◽  
Vol 16 (07) ◽  
pp. 473-484 ◽  
Author(s):  
Ruth A. Bentler
Keyword(s):  
Systematic Review ◽  
Noise Reduction ◽  
Hearing Aids ◽  
Small Sample Size ◽  
Careful Consideration ◽  
Small Sample ◽  
Experimental Conditions ◽  
Directional Microphones ◽  
Directional Microphone

A systematic review of the literature was undertaken to find evidence of real-world effectiveness of directional microphone and digital noise reduction features in current hearing aids. The evidence was drawn from randomized controlled trials, nonrandomized intervention studies, and descriptive studies. The quality of each study was evaluated for factors such as blinding, power of statistical analyses, and use of psychometrically strong outcome measures. Weaknesses in the identified studies included small sample size, resultant poor power to detect potentially worthwhile differences, and overlapping experimental conditions. Nine studies were identified for directional microphones, and the evidence (albeit weak) supports effectiveness. Two studies were identified for the noise reduction feature, and the evidence was equivocal. For the researcher, such a systematic review should encourage the careful consideration of appropriate methodologies for assessing feature effectiveness. For the clinician, the outcomes reported herein should encourage use of such a systematic review to drive clinical practice.

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