Relationship between Laboratory Measures of Directional Advantage and Everyday Success with Directional Microphone Hearing Aids

2004 ◽  
Vol 15 (05) ◽  
pp. 353-364 ◽  
Author(s):  
Mary T. Cord ◽  
Rauna K Surr ◽  
Brian E. Walden ◽  
Ole Dyrlund

The improvement in speech recognition in noise obtained with directional microphones compared to omnidirectional microphones is referred to as the directional advantage. Laboratory studies have revealed substantial differences in the magnitude of the directional advantage across hearing-impaired listeners. This investigation examined whether persons who were successful users of directional microphone hearing aids in everyday living tended to obtain a larger directional advantage in the test booth than persons who were unsuccessful users. Results revealed that the mean directional advantage did not differ significantly between patients who used the directional mode regularly and those who reported little or no benefit from directional microphones in daily living and, therefore, tended to leave their hearing aids set in the default omnidirectional mode. Success with directional microphone hearing aids in everyday living, therefore, cannot be reliably predicted by the magnitude of the directional advantage obtained in the clinic.

2006 ◽  
Vol 17 (03) ◽  
pp. 179-189 ◽  
Author(s):  
Ruth Bentler ◽  
Catherine Palmer ◽  
Gustav H. Mueller

This clinical trial was undertaken to evaluate the benefit obtained from hearing aids employing second-order adaptive directional microphone technology, used in conjunction with digital noise reduction. Data were collected for 49 subjects across two sites. New and experienced hearing aid users were fit bilaterally with behind-the-ear hearing aids using the National Acoustics Laboratory—Nonlinear version 1 (NAL-NL1) prescriptive method with manufacturer default settings for various parameters of signal processing (e.g., noise reduction, compression, etc.). Laboratory results indicated that (1) for the stationary noise environment, directional microphones provided better speech perception than omnidirectional microphones, regardless of the number of microphones; and (2) for the moving noise environment, the three-microphone option (whether in adaptive or fixed mode) and the two-microphone option in its adaptive mode resulted in better performance than the two-microphone fixed mode, or the omnidirectional modes.


1984 ◽  
Vol 49 (3) ◽  
pp. 278-286 ◽  
Author(s):  
David B. Hawkins ◽  
William S. Yacullo

The signal-to-noise ratio necessary for a constant performance level was determined for normally hearing and hearing-impaired subjects under three levels of reverberation (0.3, 0.6, and 1.2 s) with monaural and binaural hearing aids having directional and omnidirectional microphones. Results indicated (a) a significant binaural advantage (2–3 dB) which was independent of microphone type and reverberation time, (b) a significant directional microphone advantage (3–4 dB) which was independent of hearing aid arrangement (monaural or binaural) but dependent on level of reverberation, (c) a significant reverberation effect which was larger than either the binaural or directional microphone effect, and (d) additive binaural and directional microphone advantages. The results suggest that the signal-to-noise ratio is optimized when binaural hearing aids with directional microphones are used in rooms with short reverberation times.


2002 ◽  
Vol 13 (06) ◽  
pp. 295-307 ◽  
Author(s):  
Mary T. Cord ◽  
Rauna K. Surr ◽  
Brian E. Walden ◽  
Laurel Olson

This study explored the use patterns and benefits of directional microphone technology in real world situations experienced by patients who had been fitted with switchable omnidirectional/directional hearing aids. Telephone interviews and paper-and-pencil questionnaires were used to assess perceived performance with each microphone type in a variety of listening situations. Patients who used their hearing aids regularly and switched between the two microphone configurations reported using the directional mode, on average, about one-quarter of the time. From brief descriptions, patients could identify listening situations in which each microphone mode should provide superior performance. Further, they reported encountering listening situations in which an omnidirectional microphone should provide better performance more frequently than listening situations in which the directional microphones should be superior. Despite using the omnidirectional mode more often and encountering situations in which an omnidirectional microphone should provide superior performance more frequently, participants reported the same level of satisfaction with each microphone type.


2005 ◽  
Vol 16 (07) ◽  
pp. 473-484 ◽  
Author(s):  
Ruth A. Bentler

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.


2004 ◽  
Vol 15 (06) ◽  
pp. 440-455 ◽  
Author(s):  
Cynthia L. Compton-Conley ◽  
Arlene C. Neuman ◽  
Mead C. Killion ◽  
Harry Levitt

The purpose of this study was to assess the accuracy of clinical and laboratory measures of directional microphone benefit. Three methods of simulating a noisy restaurant listening situation ([1] a multimicrophone/multiloudspeaker simulation, the R-SPACE™, [2] a single noise source behind the listener, and [3] a single noise source above the listener) were evaluated and compared to the "live" condition. Performance with three directional microphone systems differing in polar pattern (omnidirectional, supercardioid, and hypercardioid array) and directivity indices (0.34, 4.20, and 7.71) was assessed using a modified version of the Hearing in Noise Test (HINT). The evaluation revealed that the three microphones could be ordered with regard to the benefit obtained using any of the simulation techniques. However, the absolute performance obtained with each microphone type differed among simulations. Only the R-SPACE simulation yielded accurate estimates of the absolute performance of all three microphones in the live condition. Performance in the R-SPACE condition was not significantly different from performance in the "live restaurant" condition. Neither of the single noise source simulations provided accurate predictions of real-world (live) performance for all three microphones.


2013 ◽  
Vol 24 (06) ◽  
pp. 474-485 ◽  
Author(s):  
Yu-Hsiang Wu ◽  
Elizabeth Stangl ◽  
Ruth A. Bentler ◽  
Rachel W. Stanziola

Background: Communication while traveling in an automobile often is very difficult for hearing aid users. This is because the automobile/road noise level is usually high, and listeners/drivers often do not have access to visual cues. Since the talker of interest usually is not located in front of the listener/driver, conventional directional processing that places the directivity beam toward the listener's front may not be helpful and, in fact, could have a negative impact on speech recognition (when compared to omnidirectional processing). Recently, technologies have become available in commercial hearing aids that are designed to improve speech recognition and/or listening effort in noisy conditions where talkers are located behind or beside the listener. These technologies include (1) a directional microphone system that uses a backward-facing directivity pattern (Back-DIR processing), (2) a technology that transmits audio signals from the ear with the better signal-to-noise ratio (SNR) to the ear with the poorer SNR (Side-Transmission processing), and (3) a signal processing scheme that suppresses the noise at the ear with the poorer SNR (Side-Suppression processing). Purpose: The purpose of the current study was to determine the effect of (1) conventional directional microphones and (2) newer signal processing schemes (Back-DIR, Side-Transmission, and Side-Suppression) on listener's speech recognition performance and preference for communication in a traveling automobile. Research Design: A single-blinded, repeated-measures design was used. Study Sample: Twenty-five adults with bilateral symmetrical sensorineural hearing loss aged 44 through 84 yr participated in the study. Data Collection and Analysis: The automobile/road noise and sentences of the Connected Speech Test (CST) were recorded through hearing aids in a standard van moving at a speed of 70 mph on a paved highway. The hearing aids were programmed to omnidirectional microphone, conventional adaptive directional microphone, and the three newer schemes. CST sentences were presented from the side and back of the hearing aids, which were placed on the ears of a manikin. The recorded stimuli were presented to listeners via earphones in a sound-treated booth to assess speech recognition performance and preference with each programmed condition. Results: Compared to omnidirectional microphones, conventional adaptive directional processing had a detrimental effect on speech recognition when speech was presented from the back or side of the listener. Back-DIR and Side-Transmission processing improved speech recognition performance (relative to both omnidirectional and adaptive directional processing) when speech was from the back and side, respectively. The performance with Side-Suppression processing was better than with adaptive directional processing when speech was from the side. The participants' preferences for a given processing scheme were generally consistent with speech recognition results. Conclusions: The finding that performance with adaptive directional processing was poorer than with omnidirectional microphones demonstrates the importance of selecting the correct microphone technology for different listening situations. The results also suggest the feasibility of using hearing aid technologies to provide a better listening experience for hearing aid users in automobiles.


2021 ◽  
Vol 4 (2) ◽  
pp. 45-50
Author(s):  
Ecem KARTAL ÖZCAN ◽  
Merve ÖZBAL BATUK ◽  
Şule KAYA ◽  
Gonca SENNAROĞLU

Assessment of speech perception in noise in children with hearing aids: Preliminary results* Objective: Noisy environments are a part of the daily life of children, just like adults. Children with hearing loss who wear hearing aids are more susceptible to the negative effects of noise than their normal-hearing peers. This study aims to evaluate the speech recognition in noise performance of hearing aid users and compare them with their normal-hearing peers. Material and Method: Five children aged 6-12 years with bilateral moderate to severe symmetrical sensorineural hearing loss and using bilateral behind-the-ear hearing aids were included in the study. 4 different conditions of the Turkish HINT-C were applied, and a speech recognition threshold (SRT) is determined for each condition. Results: Regardless of their age, the SRT needed by children with hearing aids to achieve equal performance with their normal-hearing peers was found to be higher for all test conditions. As seen in children with normal hearing in general, the mean noise front score of the children with hearing loss was higher than the mean noise right and noise left scores. Conclusion: The results of this study revealed that children with bilaterally symmetrical moderate to severe hearing loss achieved poor speech recognition scores in environments similar to the classroom environment, compared to their normal-hearing peers. Our results guided appropriate rehabilitation and follow-up. Keywords: noise, speech recognition in noise, hearing loss, hearing aid, pediatric audiology, HINT, HINT-C


2004 ◽  
Vol 15 (05) ◽  
pp. 342-352 ◽  
Author(s):  
Therese C. Walden ◽  
Brian E. Walden

Persons with impaired hearing who are candidates for amplification are not all equally successful with hearing aids in daily living. Having the ability to predict success with amplification in everyday life from measures that can be obtained during an initial evaluation of the patient's candidacy would result in greater patient satisfaction with hearing aids and more efficient use of clinical resources. This study investigated the relationship between various demographic and audiometric measures, and two measures of hearing aid success in 50 hearing aid wearers. Audiometric predictors included measures of audibility and suprathreshold distortion. The unaided and aided signal-to-noise ratio (SNR) loss on the QuickSIN test provided the best predictors of hearing aid success in daily living. However, much of this predictive relationship appeared attributable to the patient's age.


2004 ◽  
Vol 15 (05) ◽  
pp. 365-396 ◽  
Author(s):  
Brian E. Walden ◽  
Rauna K. Surr ◽  
Mary T. Cord ◽  
Ole Dyrlund

Seventeen hearing-impaired adults were fit with omnidirectional/directional hearing aids, which they wore during a four-week trial. For each listening situation encountered in daily living during a total of seven days, participants selected the preferred microphone mode and described the listening situation in terms of five environmental variables, using a paper and pencil form. Results indicated that hearing-impaired adults typically spend the majority of their active listening time in situations with background noise present and surrounding the listener, and the signal source located in front and relatively near. Microphone preferences were fairly evenly distributed across listening situations but differed depending on the characteristics of the listening environment. The omnidirectional mode tended to be preferred in relatively quiet listening situations or, in the presence of background noise, when the signal source was relatively far away. The directional mode tended to be preferred when background noise was present and the signal source was located in front of and relatively near the listener. Results suggest that knowing only signal location and distance and whether background noise is present or absent, omnidirectional/directional hearing aids can be set in the preferred mode in most everyday listening situations. These findings have relevance for counseling patients when to set manually switchable omnidirectional/directional hearing aids in each microphone mode, as well as for the development of automatic algorithms for selecting omnidirectional versus directional microphone processing.


2004 ◽  
Vol 15 (09) ◽  
pp. 649-659 ◽  
Author(s):  
Ruth A. Bentler ◽  
Jessica L.M. Egge ◽  
Jill L. Tubbs ◽  
Andrew B. Dittberner ◽  
Gregory A. Flamme

The purpose of this study was to assess the relationship between the directivity of a directional microphone hearing aid and listener performance. Hearing aids were fit bilaterally to 19 subjects with sensorineural hearing loss, and five microphone conditions were assessed: omnidirectional, cardioid, hypercardioid, supercardioid, and "monofit," wherein the left hearing aid was set to omnidirectional and the right hearing aid to hypercardioid. Speech perception performance was assessed using the Hearing in Noise Test (HINT) and the Connected Speech Test (CST). Subjects also assessed eight domains of sound quality for three stimuli (speech in quiet, speech in noise, and music). A diffuse soundfield system composed of eight loudspeakers forming the corners of a cube was used to output the background noise for the speech perception tasks and the three stimuli used for sound quality judgments. Results indicated that there were no significant differences in the HINT or CST performance, or sound quality judgments, across the four directional microphone conditions when tested in a diffuse field. Of particular interest was the monofit condition: Performance on speech perception tests was the same whether one or two directional microphones were used.


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