scholarly journals Noise Suppression by an Adaptive Directional Microphone in Commercial Digital Hearing Aids: Acoustical Investigation with a Moving Noise Source

2005 ◽  
Vol 48 (6) ◽  
pp. 623-632
Author(s):  
Noriko IWASAKI ◽  
Kimio SHIRAISHI
Keyword(s):  
Hearing Aids ◽  
Noise Suppression ◽  
Noise Source ◽  
Digital Hearing Aids ◽  
Directional Microphone

Performance of Directional Microphones for Hearing Aids: Real-World versus Simulation

2004 ◽  
Vol 15 (06) ◽  
pp. 440-455 ◽  
Author(s):  
Cynthia L. Compton-Conley ◽  
Arlene C. Neuman ◽  
Mead C. Killion ◽  
Harry Levitt
Keyword(s):  
Hearing Aids ◽  
Real World ◽  
Noise Source ◽  
Live Performance ◽  
Space Condition ◽  
Directional Microphones ◽  
Directional Microphone ◽  
Simulation Techniques ◽  
Hearing In Noise ◽  
The Absolute

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.

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.

Assessment of the effects of noise suppression in digital hearing aids

2003 ◽  
Vol 1240 ◽  
pp. 333-338
Author(s):  
Somia Tawfik ◽  
Marcel Vlaming ◽  
Iman Sadek ◽  
Nithreen Said ◽  
Lobna Hamed
Keyword(s):  
Hearing Aids ◽  
Noise Suppression ◽  
Digital Hearing Aids

scholarly journals Noise Reduction Using Modified Wiener Filter in Digital Hearing Aid for Speech Signal Enhancement

2019 ◽  
Vol 29 (1) ◽  
pp. 1360-1378
Author(s):  
Madam Aravind Kumar ◽  
Kamsali Manjunatha Chari
Keyword(s):  
Hearing Aids ◽  
Speech Signal ◽  
Communication Systems ◽  
Noise Suppression ◽  
Wiener Filter ◽  
Power Spectra ◽  
Noise Signal ◽  
Communication Process ◽  
Digital Hearing Aids ◽  
Multiplication Operation

Abstract Speech signals are usually affected by noises during the communication process. For suppressing the noise signal that is combined with the speech signal, a Wiener filter is adapted in digital hearing aids. Weiner filter plays an important role in noise suppression and enhancement by estimating the relation between the power spectra of the noise-affected speech signal and the noise signal. Power consumption and the hardware requirement are the important problems in adapting Weiner filter for major communication systems. In this work, we implemented an efficient Wiener filter and applied it for noise suppression along with a real-valued fast Fourier transform (FFT)/real-valued inverse FFT processor in digital hearing aids. The pipelined process was adopted for increasing the performance of the system. The proposed Wiener filter was designed to remove the iteration problems in the conventional Wiener filter. The division operation was replaced by an efficient inverse and multiplication operation in the proposed design. A modified architecture for matrix inversion with low computation complexity was implemented. The complete design computation was based on IEEE-754 standard single-precision floating-point numbers. The Wiener filter and the whole system architecture was implemented and designed on a Field Programmable Gate Array platform and simulated to validate the results in Xilinx ISE tools. An efficient reduction in power and area was obtained by adapting the proposed method for speech signal noise degradation. The performance of the proposed design was found to be 50.01% more efficient than that of existing designs.

Performance Improvement of Digital Hearing Aid Systems

2015 ◽  
Vol 1 ◽  
pp. 27
Author(s):  
Isiaka Ajewale Alimi
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Digital Signal Processor ◽  
Speech Intelligibility ◽  
Communication Systems ◽  
Hearing Aid ◽  
Spectral Subtraction ◽  
Residual Spectrum ◽  
Digital Hearing Aids ◽  
Digital Hearing Aid

Digital hearing aids addresses the issues of noise and speech intelligibility that is associated with the analogue types. One of the main functions of the digital signal processor (DSP) of digital hearing aid systems is noise reduction which can be achieved by speech enhancement algorithms which in turn improve system performance and flexibility. However, studies have shown that the quality of experience (QoE) with some of the current hearing aids is not up to expectation in a noisy environment due to interfering sound, background noise and reverberation. It is also suggested that noise reduction features of the DSP can be further improved accordingly. Recently, we proposed an adaptive spectral subtraction algorithm to enhance the performance of communication systems and address the issue of associated musical noise generated by the conventional spectral subtraction algorithm. The effectiveness of the algorithm has been confirmed by different objective and subjective evaluations. In this study, an adaptive spectral subtraction algorithm is implemented using the noise-estimation algorithm for highly non-stationary noisy environments instead of the voice activity detection (VAD) employed in our previous work due to its effectiveness. Also, signal to residual spectrum ratio (SR) is implemented in order to control the amplification distortion for speech intelligibility improvement. The results show that the proposed scheme gives comparatively better performance and can be easily employed in digital hearing aid system for improving speech quality and intelligibility.

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.

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