Performance of Directional Microphone Hearing Aids in Everyday Life

2002 ◽  
Vol 13 (06) ◽  
pp. 295-307 ◽  
Author(s):  
Mary T. Cord ◽  
Rauna K. Surr ◽  
Brian E. Walden ◽  
Laurel Olson
Keyword(s):  
Hearing Aids ◽  
Superior Performance ◽  
Directional Hearing ◽  
Directional Microphones ◽  
Use Patterns ◽  
Telephone Interviews ◽  
Directional Microphone ◽  
Perceived Performance ◽  
Level Of Satisfaction ◽  
Directional Hearing Aids

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.

Effect of Signal-to-Noise Ratio on Directional Microphone Benefit and Preference

2005 ◽  
Vol 16 (09) ◽  
pp. 662-676 ◽  
Author(s):  
Brian E. Walden ◽  
Rauna K. Surr ◽  
Kenneth W. Grant ◽  
W. Van Summers ◽  
Mary T. Cord ◽  
...  
Keyword(s):  
Hearing Aids ◽  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Directional Hearing ◽  
Signal To Noise ◽  
Directional Microphones ◽  
Directional Microphone ◽  
The Individual ◽  
Directional Hearing Aids

This study examined speech intelligibility and preferences for omnidirectional and directional microphone hearing aid processing across a range of signal-to-noise ratios (SNRs). A primary motivation for the study was to determine whether SNR might be used to represent distance between talker and listener in automatic directionality algorithms based on scene analysis. Participants were current hearing aid users who either had experience with omnidirectional microphone hearing aids only or with manually switchable omnidirectional/directional hearing aids. Using IEEE/Harvard sentences from a front loudspeaker and speech-shaped noise from three loudspeakers located behind and to the sides of the listener, the directional advantage (DA) was obtained at 11 SNRs ranging from -15 dB to +15 dB in 3 dB steps. Preferences for the two microphone modes at each of the 11 SNRs were also obtained using concatenated IEEE sentences presented in the speech-shaped noise. Results revealed that a DA was observed across a broad range of SNRs, although directional processing provided the greatest benefit within a narrower range of SNRs. Mean data suggested that microphone preferences were determined largely by the DA, such that the greater the benefit to speech intelligibility provided by the directional microphones, the more likely the listeners were to prefer that processing mode. However, inspection of the individual data revealed that highly predictive relationships did not exist for most individual participants. Few preferences for omnidirectional processing were observed. Overall, the results did not support the use of SNR to estimate the effects of distance between talker and listener in automatic directionality algorithms.

Making Sense of Directional Microphone Hearing Aids

1999 ◽  
Vol 8 (2) ◽  
pp. 117-127 ◽  
Author(s):  
Todd Ricketts ◽  
H. Gustav Mueller
Keyword(s):  
Hearing Aids ◽  
Directional Hearing ◽  
Laboratory Assessment ◽  
Digital Hearing Aids ◽  
Making Sense ◽  
Directional Microphone ◽  
Short Course ◽  
Digitally Controlled ◽  
Potential Impact ◽  
Directional Hearing Aids

We have witnessed a large increase in the availability of directional microphone hearing aids over the past few years. Directional microphone technology is now available in analog, digitally controlled analog, and digital hearing aids, and has been implemented into both behind-the-ear and in-the-ear styles. This Short Course reviews basic design differences across directional microphone hearing aids. A number of different laboratory and clinical evaluation methods used for assessment of both electroacoustic and behavioral directivity are then reviewed. In addition, the potential impact of test conditions such as room reverberation and type and position of competing noise(s), on listener performance when fit with directional hearing aids are considered. Recommendations and suggestions relating to the clinical and laboratory assessment of directional hearing aids are provided.

Predicting Hearing Aid Microphone Preference in Everyday Listening

2004 ◽  
Vol 15 (05) ◽  
pp. 365-396 ◽  
Author(s):  
Brian E. Walden ◽  
Rauna K. Surr ◽  
Mary T. Cord ◽  
Ole Dyrlund
Keyword(s):  
Hearing Aids ◽  
Background Noise ◽  
Environmental Variables ◽  
Daily Living ◽  
Hearing Impaired ◽  
Directional Hearing ◽  
Active Listening ◽  
Signal Source ◽  
Directional Microphone ◽  
Directional Hearing Aids

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.

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.

Directional Hearing Aids: A Case Study

2005 ◽  
Vol 26 (02) ◽  
pp. 78-80
Author(s):  
Jennifer E Weber
Keyword(s):  
Hearing Aids ◽  
Directional Hearing ◽  
Directional Hearing Aids

Low-Frequency Gain Compensation in Directional Hearing Aids

2002 ◽  
Vol 11 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Todd Ricketts ◽  
Paula Henry
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Low Frequency ◽  
Sound Quality ◽  
Directional Hearing ◽  
Low Frequencies ◽  
Speech In Noise ◽  
Directional Microphone ◽  
Listening Environments ◽  
Gain Compensation

Hearing aids currently available on the market with both omnidirectional and directional microphone modes often have reduced amplification in the low frequencies when in directional microphone mode due to better phase matching. The effects of this low-frequency gain reduction for individuals with hearing loss in the low frequencies was of primary interest. Changes in sound quality for quiet listening environments following gain compensation in the low frequencies was of secondary interest. Thirty participants were fit with bilateral in-the-ear hearing aids, which were programmed in three ways while in directional microphone mode: no-gain compensation, adaptive-gain compensation, and full-gain compensation. All participants were tested with speech in noise tasks. Participants also made sound quality judgments based on monaural recordings made from the hearing aid. Results support a need for gain compensation for individuals with low-frequency hearing loss of greater than 40 dB HL.

Predictability of Speech-In-Noise Performance from Real Ear Measures of Directional Hearing Aids

2004 ◽  
Vol 25 (2) ◽  
pp. 147-158 ◽  
Author(s):  
Sumitrajit Dhar ◽  
Larry E. Humes ◽  
Lauren Calandruccio ◽  
Nancy N. Barlow ◽  
Nicholas Hipskind
Keyword(s):  
Hearing Aids ◽  
Directional Hearing ◽  
Noise Performance ◽  
Speech In Noise ◽  
Directional Hearing Aids
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