scholarly journals Perceptual Evaluation of Signal-to-Noise-Ratio-Aware Dynamic Range Compression in Hearing Aids

2020 ◽  
Vol 24 ◽  
pp. 233121652093053
Author(s):  
Borys Kowalewski ◽  
Torsten Dau ◽  
Tobias May
Keyword(s):  
Hearing Aids ◽  
Speech Intelligibility ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Perceptual Evaluation ◽  
Dynamic Range Compression ◽  
Subjective Preference ◽  
Noise Ratio ◽  
Fast Acting

Dynamic range compression is a compensation strategy commonly used in modern hearing aids. Fast-acting systems respond relatively quickly to the fluctuations in the input level. This allows for more effective compression of the dynamic range of speech and hence enhanced the audibility of its low-intensity components. However, such processing also amplifies the background noise, distorts the modulation spectra of both the speech and the background, and can reduce the output signal-to-noise ratio (SNR). Recently, May et al. proposed a novel SNR-aware compression strategy, in which the compression speed is adapted depending on whether speech is present or absent. Fast-acting compression is applied to speech-dominated time–frequency (T-F) units, while noise-dominated T-F units are processed using slow-acting compression. It has been shown that this strategy provides a similar effective compression of the speech dynamic range as conventional fast-acting compression, while introducing fewer distortions of the modulation spectrum of the background and providing an improved output SNR. In this study, this SNR-aware compression strategy was compared with conventional fast- and slow-acting compression in terms of speech intelligibility and subjective preference in a group of 17 hearing-impaired listeners with varying degree of hearing loss. The results show a speech intelligibility benefit of the SNR-aware compression strategy over the conventional slow-acting system. Furthermore, the SNR-aware approach demonstrates an increased subjective preference compared with both conventional fast- and slow-acting systems.

scholarly journals Signal-to-Noise-Ratio-Aware Dynamic Range Compression in Hearing Aids

2018 ◽  
Vol 22 ◽  
pp. 233121651879090 ◽  
Author(s):  
Tobias May ◽  
Borys Kowalewski ◽  
Torsten Dau
Keyword(s):  
Hearing Aids ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Dynamic Range Compression ◽  
Noise Ratio

Acoustical and Perceptual Comparison of Noise Reduction and Compression in Hearing Aids

2015 ◽  
Vol 58 (4) ◽  
pp. 1363-1376 ◽  
Author(s):  
Inge Brons ◽  
Rolph Houben ◽  
Wouter A. Dreschler
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Speech Intelligibility ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Noise Levels ◽  
Dynamic Range Compression ◽  
Perceptual Comparison ◽  
Babble Noise ◽  
Processing Differences

Purpose Noise reduction and dynamic-range compression are generally applied together in hearing aids but may have opposite effects on amplification. This study evaluated the acoustical and perceptual effects of separate and combined processing of noise reduction and compression. Design Recordings of the output of 4 hearing aids for speech in babble noise at +4 dB signal-to-noise ratio were used in 3 experiments: (a) acoustical measurements to determine the influence of processing on speech and noise levels; (b) perceptual measurements to determine the detectability of processing differences for 16 listeners with hearing impairment; and (c) perceptual measurements to determine the effect of processing on speech intelligibility, noise annoyance, speech naturalness, and overall preference. Results Noise reduction and compression processing differed between hearing aids. The combined processing (noise reduction with compression) most strongly reduced noise and speech levels. The combined processing was detectably different between hearing aids, but compression processing alone was not. The combined processing did not influence speech intelligibility. Preference for combined processing was lower than previously observed for noise reduction without compression. Conclusions Differences in processing between hearing aids are perceptually salient. The effect of compression should be taken into account during the development and evaluation of hearing aid noise reduction.

An Over 120dB Dynamic Range Linear Response Single Exposure CMOS Image Sensor with Two-stage Lateral Overflow Integration Trench Capacitors

2020 ◽  
Vol 2020 (7) ◽  
pp. 143-1-143-6 ◽  
Author(s):  
Yasuyuki Fujihara ◽  
Maasa Murata ◽  
Shota Nakayama ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Linear Response ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Signal To Noise ◽  
Single Exposure ◽  
Two Stage ◽  
Noise Ratio ◽  
Maximum Signal

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.

Singular Values Decomposition and Lifting Wavelet Transform for Speech Signal Embedding into Digital Image

2019 ◽  
Vol 12 (2) ◽  
pp. 138-151
Author(s):  
Mourad Talbi ◽  
Med Salim Bouhlel
Keyword(s):  
Wavelet Transform ◽  
Speech Signal ◽  
Signal To Noise Ratio ◽  
Perceptual Quality ◽  
Lifting Wavelet Transform ◽  
Signal To Noise ◽  
Perceptual Evaluation ◽  
Lifting Wavelet ◽  
Noise Ratio

Background: In this paper, we propose a secure image watermarking technique which is applied to grayscale and color images. It consists in applying the SVD (Singular Value Decomposition) in the Lifting Wavelet Transform domain for embedding a speech image (the watermark) into the host image. Methods: It also uses signature in the embedding and extraction steps. Its performance is justified by the computation of PSNR (Pick Signal to Noise Ratio), SSIM (Structural Similarity), SNR (Signal to Noise Ratio), SegSNR (Segmental SNR) and PESQ (Perceptual Evaluation Speech Quality). Results: The PSNR and SSIM are used for evaluating the perceptual quality of the watermarked image compared to the original image. The SNR, SegSNR and PESQ are used for evaluating the perceptual quality of the reconstructed or extracted speech signal compared to the original speech signal. Conclusion: The Results obtained from computation of PSNR, SSIM, SNR, SegSNR and PESQ show the performance of the proposed technique.

scholarly journals Evaluation of an Adaptive Dynamic Compensation System in Cochlear Implant Listeners

2020 ◽  
Vol 24 ◽  
pp. 233121652097034
Author(s):  
Florian Langner ◽  
Andreas Büchner ◽  
Waldo Nogueira
Keyword(s):  
Signal Processing ◽  
Cochlear Implant ◽  
Speech Intelligibility ◽  
Discrimination Task ◽  
Signal To Noise Ratio ◽  
Compensation System ◽  
Signal To Noise ◽  
Dynamic Compensation ◽  
Front End ◽  
Noise Ratio

Cochlear implant (CI) sound processing typically uses a front-end automatic gain control (AGC), reducing the acoustic dynamic range (DR) to control the output level and protect the signal processing against large amplitude changes. It can also introduce distortions into the signal and does not allow a direct mapping between acoustic input and electric output. For speech in noise, a reduction in DR can result in lower speech intelligibility due to compressed modulations of speech. This study proposes to implement a CI signal processing scheme consisting of a full acoustic DR with adaptive properties to improve the signal-to-noise ratio and overall speech intelligibility. Measurements based on the Short-Time Objective Intelligibility measure and an electrodogram analysis, as well as behavioral tests in up to 10 CI users, were used to compare performance with a single-channel, dual-loop, front-end AGC and with an adaptive back-end multiband dynamic compensation system (Voice Guard [VG]). Speech intelligibility in quiet and at a +10 dB signal-to-noise ratio was assessed with the Hochmair–Schulz–Moser sentence test. A logatome discrimination task with different consonants was performed in quiet. Speech intelligibility was significantly higher in quiet for VG than for AGC, but intelligibility was similar in noise. Participants obtained significantly better scores with VG than AGC in the logatome discrimination task. The objective measurements predicted significantly better performance estimates for VG. Overall, a dynamic compensation system can outperform a single-stage compression (AGC + linear compression) for speech perception in quiet.

A Test to Measure Subjective and Objective Speech Intelligibility

2002 ◽  
Vol 13 (01) ◽  
pp. 038-049 ◽  
Author(s):  
Gabrielle H. Saunders ◽  
Kathleen M. Cienkowski
Keyword(s):  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Clinical Tool ◽  
Signal To Noise ◽  
Speech Reception ◽  
Measurement Signal ◽  
Perceptual Performance ◽  
Noise Ratio ◽  
Performance Discrepancy

Measurement of hearing aid outcome is particularly difficult because there are numerous dimensions to consider (e.g., performance, satisfaction, benefit). Often there are discrepancies between scores in these dimensions. It is difficult to reconcile these discrepancies because the materials and formats used to measure each dimension are so very different. We report data obtained with an outcome measure that examines both objective and subjective dimensions with the same test format and materials and gives results in the same unit of measurement (signal-to-noise ratio). Two variables are measured: a “performance” speech reception threshold and a “perceptual” speech reception threshold. The signal-to-noise ratio difference between these is computed to determine the perceptual-performance discrepancy (PPDIS). The results showed that, on average, 48 percent of the variance in subjective ratings of a hearing aid could be explained by a combination of the performance speech reception threshold and the PPDIS. These findings suggest that the measure is potentially a valuable clinical tool.

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