Noise Reduction Results of an Adaptive Filtering Technique for Dual-Microphone Behind-the-Ear Hearing Aids

In this paper, we present a noise reduction technique for hearing-aid systems. The proposed algorithm adopted adaptive beamformer with combination of subband filtering technique. The structure of conventional hearing aids is relatively simple. They amplify ambient sounds that include speech signal as well as noise. Because noise and human speech signal are amplified at the same time, hearing-aid users can't clearly hear speech signal in noisy environment. The direction of sound can be used to discriminate speech signal from noise by combining adaptive noise canceller and adaptive beamformer. We have developed a system that based on the constrained adaptive noise canceller to preserve speech signal from straight ahead and minimize background noise arriving from other directions. This system also uses subband filtering technique to reduce the requirement for computation and enhance the flexibility of the system. The performance of this system is illustrated using simulated and real-world noises. The results show that the developed system can reserve the right ahead speech signal and substantially reject noises from other directions.

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A real time implementation and an evaluation of an optimal filtering technique for noise reduction in dual microphone hearing aids

2004 IEEE International Conference on Acoustics, Speech, and Signal Processing ◽

10.1109/icassp.2004.1326750 ◽

2004 ◽

Author(s):

J.B. Maj ◽

L. Royackers ◽

J. Wouters

Keyword(s):

Noise Reduction ◽

Real Time ◽

Hearing Aids ◽

Optimal Filtering ◽

Filtering Technique

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Performance Improvement of Digital Hearing Aid Systems

Journal of Communications Technology Electronics and Computer Science ◽

10.22385/jctecs.v1i0.15 ◽

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.

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Measuring the Influence of Noise Reduction on Listening Effort in Hearing-Impaired Listeners Using Response Times to an Arithmetic Task in Noise

Trends in Hearing ◽

10.1177/23312165211014437 ◽

2021 ◽

Vol 25 ◽

pp. 233121652110144

Author(s):

Ilja Reinten ◽

Inge De Ronde-Brons ◽

Rolph Houben ◽

Wouter Dreschler

Keyword(s):

Noise Reduction ◽

Hearing Aids ◽

Speech Intelligibility ◽

Response Times ◽

Hearing Impaired ◽

Listening Effort ◽

Arithmetic Task ◽

Test Retest Reliability ◽

Influence Of Noise ◽

Measured Response

Single microphone noise reduction (NR) in hearing aids can provide a subjective benefit even when there is no objective improvement in speech intelligibility. A possible explanation lies in a reduction of listening effort. Previously, we showed that response times (a proxy for listening effort) to an auditory-only dual-task were reduced by NR in normal-hearing (NH) listeners. In this study, we investigate if the results from NH listeners extend to the hearing-impaired (HI), the target group for hearing aids. In addition, we assess the relevance of the outcome measure for studying and understanding listening effort. Twelve HI subjects were asked to sum two digits of a digit triplet in noise. We measured response times to this task, as well as subjective listening effort and speech intelligibility. Stimuli were presented at three signal-to-noise ratios (SNR; –5, 0, +5 dB) and in quiet. Stimuli were processed with ideal or nonideal NR, or unprocessed. The effect of NR on response times in HI listeners was significant only in conditions where speech intelligibility was also affected (–5 dB SNR). This is in contrast to the previous results with NH listeners. There was a significant effect of SNR on response times for HI listeners. The response time measure was reasonably correlated ( R142 = 0.54) to subjective listening effort and showed a sufficient test–retest reliability. This study thus presents an objective, valid, and reliable measure for evaluating an aspect of listening effort of HI listeners.

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