Cascaded Structure of Noise Reduction and Multiband Frequency Compression of speech signal to Improve Speech Perception for monaural Hearing Aids

Author(s):  
Rajani S. Pujar ◽  
P. N. Kulkarni
2020 ◽  
Vol 24 (4) ◽  
pp. 180-190
Author(s):  
Hyo Jeong Kim ◽  
Jae Hee Lee ◽  
Hyun Joon Shim

Background and Objectives: Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. Subjects and Methods: Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. Results: There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (<i>p</i>=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (<i>p</i>=0.029). Conclusions: Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener’s subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.


2013 ◽  
Vol 24 (09) ◽  
pp. 832-844 ◽  
Author(s):  
Andrea L. Pittman ◽  
Mollie M. Hiipakka

Background: Before advanced noise-management features can be recommended for use in children with hearing loss, evidence regarding their ability to use these features to optimize speech perception is necessary. Purpose: The purpose of this study was to examine the relation between children's preference for, and performance with, four combinations of noise-management features in noisy listening environments. Research Design: Children with hearing loss were asked to repeat short sentences presented in steady-state noise or in multitalker babble while wearing ear-level hearing aids. The aids were programmed with four memories having an orthogonal arrangement of two noise-management features. The children were also asked to indicate the hearing aid memory that they preferred in each of the listening conditions both initially and after a short period of use. Study Sample: Fifteen children between the ages of 8 and 12 yr with moderate hearing losses, bilaterally. Results: The children's preference for noise management aligned well with their performance for at least three of the four listening conditions. The configuration of noise-management features had little effect on speech perception with the exception of reduced performance for speech originating from behind the child while in a directional hearing aid setting. Additionally, the children's preference appeared to be governed by listening comfort, even under conditions for which a benefit was not expected such as the use of digital noise reduction in the multitalker babble conditions. Conclusions: The results serve as evidence in support of the use of noise-management features in grade-school children as young as 8 yr of age.


This paper introduces technology to improve sound quality, which serves the needs of media and entertainment. Major challenging problem in the speech processing applications like mobile phones, hands-free phones, car communication, teleconference systems, hearing aids, voice coders, automatic speech recognition and forensics etc., is to eliminate the background noise. Speech enhancement algorithms are widely used for these applications in order to remove the noise from degraded speech in the noisy environment. Hence, the conventional noise reduction methods introduce more residual noise and speech distortion. So, it has been found that the noise reduction process is more effective to improve the speech quality but it affects the intelligibility of the clean speech signal. In this paper, we introduce a new model of coherence-based noise reduction method for the complex noise environment in which a target speech coexists with a coherent noise around. From the coherence model, the information of speech presence probability is added to better track noise variation accurately; and during the speech presence and speech absent period, adaptive coherence-based method is adjusted. The performance of suggested method is evaluated in condition of diffuse and real street noise, and it improves the speech signal quality less speech distortion and residual noise.


2020 ◽  
Vol 63 (12) ◽  
pp. 4208-4218
Author(s):  
Priyanka Jaisinghani ◽  
P. Manjula

Purpose The conventional amplification devices render minimal or no benefit at abating the speech perception problems of individuals with auditory neuropathy spectrum disorder (ANSD). This study was undertaken to evaluate the effect of noise reduction strategies (multiband spectral subtraction, Wiener-as, Karhunen–Loeve transform [Subspace], and ideal binary mask [IdBM] algorithm) on speech using speech perception measures and acoustic measure among individuals with ANSD. Method Two groups of participants (age: 17–43 years) were recruited in the study. Group I comprised 12 individuals with a confirmed diagnosis of ANSD and not exceeding moderate degree of hearing loss and Group II of 10 individuals with normal hearing in both ears. The signal-to-noise required for 50% speech recognition (SNR-50) was measured for the participants in five conditions, that is, unprocessed speech and speech processed with four noise reduction strategies. Additionally, an acoustic objective measure Extended Short-Time Objective Intelligibility algorithm was employed to estimate the intelligibility index across the conditions. Results Significant difference was found across conditions in both the groups. Pairwise comparison revealed significantly better speech perception on SNR-50 measure with IdBM strategy, for both the groups. No significant difference in SNR-50 was observed with other noise reduction strategies. IdBM condition also gave the highest intelligibility index ( d ) values using Extended Short-Time Objective Intelligibility algorithm. This finding needs to be verified on a larger group of individuals with ANSD. Conclusions IdBM noise reduction strategy rendered significantly lower SNR-50 compared to other noise reduction strategies for individuals with ANSD in this study. This provides clinical evidence for the same and also recommends trying on a larger group of participants before its implementation in hearing devices. Apart from this, the current strategies used in hearing aids provide no improvement in speech identification in noise for this population. Hence, though the present hearing aids may show benefit in quiet condition, chances of its rejection are high in noisy backgrounds.


2009 ◽  
Vol 7 (2) ◽  
pp. 106-111 ◽  
Author(s):  
Silvano Prosser ◽  
Mauro Pulga ◽  
Antonio Mancuso ◽  
Lorenzo Picinali

2002 ◽  
Vol 6 (4) ◽  
pp. 131-165 ◽  
Author(s):  
Pamela E. Souza

The topic of compression has been discussed quite extensively in the last 20 years (eg, Braida et al., 1982; Dillon, 1996 , 2000 ; Dreschler, 1992 ; Hickson, 1994 ; Kuk, 2000 and 2002; Kuk and Ludvigsen, 1999 ; Moore, 1990 ; Van Tasell, 1993 ; Venema, 2000 ; Verschuure et al., 1996; Walker and Dillon, 1982 ). However, the latest comprehensive update by this journal was published in 1996 ( Kuk, 1996 ). Since that time, use of compression hearing aids has increased dramatically, from half of hearing aids dispensed only 5 years ago to four out of five hearing aids dispensed today ( Strom, 2002b ). Most of today's digital and digitally programmable hearing aids are compression devices ( Strom, 2002a ). It is probable that within a few years, very few patients will be fit with linear hearing aids. Furthermore, compression has increased in complexity, with greater numbers of parameters under the clinician's control. Ideally, these changes will translate to greater flexibility and precision in fitting and selection. However, they also increase the need for information about the effects of compression amplification on speech perception and speech quality. As evidenced by the large number of sessions at professional conferences on fitting compression hearing aids, clinicians continue to have questions about compression technology and when and how it should be used. How does compression work? Who are the best candidates for this technology? How should adjustable parameters be set to provide optimal speech recognition? What effect will compression have on speech quality? These and other questions continue to drive our interest in this technology. This article reviews the effects of compression on the speech signal and the implications for speech intelligibility, quality, and design of clinical procedures.


2017 ◽  
Vol 26 (4) ◽  
pp. 531-542 ◽  
Author(s):  
Danielle Glista ◽  
Marianne Hawkins ◽  
Andrea Bohnert ◽  
Julia Rehmann ◽  
Jace Wolfe ◽  
...  

Purpose This study implemented a fitting method, developed for use with frequency lowering hearing aids, across multiple testing sites, participants, and hearing aid conditions to evaluate speech perception with a novel type of frequency lowering. Method A total of 8 participants, including children and young adults, participated in real-world hearing aid trials. A blinded crossover design, including posttrial withdrawal testing, was used to assess aided phoneme perception. The hearing aid conditions included adaptive nonlinear frequency compression (NFC), static NFC, and conventional processing. Results Enabling either adaptive NFC or static NFC improved group-level detection and recognition results for some high-frequency phonemes, when compared with conventional processing. Mean results for the distinction component of the Phoneme Perception Test (Schmitt, Winkler, Boretzki, & Holube, 2016) were similar to those obtained with conventional processing. Conclusions Findings suggest that both types of NFC tested in this study provided a similar amount of speech perception benefit, when compared with group-level performance with conventional hearing aid technology. Individual-level results are presented with discussion around patterns of results that differ from the group average.


2010 ◽  
Vol 21 (06) ◽  
pp. 380-389 ◽  
Author(s):  
Hugh McDermott ◽  
Katherine Henshall

Background: The number of cochlear implant (CI) recipients who have usable acoustic hearing in at least one ear is continuing to grow. Many such CI users gain perceptual benefits from the simultaneous use of acoustic and electric hearing. In particular, it has been shown previously that use of an acoustic hearing aid (HA) with a CI can often improve speech understanding in noise. Purpose: To determine whether the application of frequency compression in an HA would provide perceptual benefits to CI recipients with usable acoustic hearing, either when used in combination with the CI or when the HA was used by itself. Research Design: A repeated-measures experimental design was used to evaluate the effects on speech perception of using a CI either alone or simultaneously with an HA that had frequency compression either enabled or disabled. Study Sample: Eight adult CI recipients who were successful users of acoustic hearing aids in their nonimplanted ears participated as subjects. Intervention: The speech perception of each subject was assessed in seven conditions. These required each subject to listen with (1) their own HA alone; (2) the Phonak Naida HA with frequency compression (SoundRecover) enabled; (3) the Naida with SoundRecover disabled; (4) their CI alone; (5) their CI and their own HA; (6) their CI and the Naida with SoundRecover enabled; and (7) their CI and the Naida with SoundRecover disabled. Test sessions were scheduled over a period of about 10 wk. During part of that time, the subjects were asked to use the Phonak Naida HA with their CIs in place of their own HAs. Data Collection and Analysis: The speech perception tests included measures of consonant identification from a closed set of 12 items presented in quiet, and measures of sentence understanding in babble noise. The speech materials were presented at an average level of 60 dB SPL from a loudspeaker. Results: Speech perception was better, on average, in all conditions that included use of the CI in comparison with any condition in which only an HA was used. For example, consonant recognition improved by approximately 50 percentage points, on average, between the HA-alone listening conditions and the CI-alone condition. There were no statistically significant score differences between conditions with SoundRecover enabled and disabled. There was a small but significant improvement in the average signal-to-noise ratio (SNR) required to understand 50% of the words in the sentences presented in noise when an HA was used simultaneously with the CI. Conclusions: Although each of these CI users readily accepted the Phonak Naida HA with SoundRecover frequency compression, no benefits related specifically to the use of SoundRecover were found in the particular tests of speech understanding applied in this study. The relatively high levels of perceptual performance attained by these subjects with use of a CI by itself are consistent with the finding that the addition of an HA provided little further benefit. However, the use of an HA with the CI did provide better performance than the CI alone for understanding sentences in noise.


2019 ◽  
Vol 23 (04) ◽  
pp. e433-e439
Author(s):  
Hemanth Narayan Shetty ◽  
Navya Bilijagalemole Nanjundaswamy

Introduction Studies have reported that although speech perception in noise was unaltered with and without digital noise reduction (DNR), the annoyance toward noise measured by acceptable noise level (ANL) was significantly improved by DNR with the range between 2.5 and 4.5 dB. It is unclear whether a similar improvement would be observed in those individuals who have an ANL ≥ 14 dB (predictive of poor hearing aid user) often rejects their aid because of annoyance toward noise. Objectives (a) To determine the effect of activation of DNR on the improvement in the aided ANL from low- and high-ANL groups; and (b) to predict the change in ANL when DNR was activated. Method Ten bilateral mild to severe sloping sensorineural hearing loss (SNHL) participants in each of the low- and high-ANL groups were involved. These participants were bilaterally fitted with receiver in canal (RIC) hearing aids (Oticon, Smorum, Egedal, Denmark) with a DNR processor. Both SNR-50% (Signal to noise ratio (in dB) required to achieve 50 % speech recognition) and ANL were assessed in DNR-on and DNR-off listening conditions. Results Digital noise reduction has no effect on SNR-50 in each group. The annoyance level was significantly reduced in the DNR-on than DNR-off condition in the low-ANL group. In the high-ANL group, a strong negative correlation was observed between the ANL in DNR off and a change in ANL after DNR was employed in the hearing aid (benefit). The benefit of DNR on annoyance can be effectively predicted by baseline-aided ANL by linear regression. Conclusion Digital noise reduction reduced the annoyance level in the high-ANL group, and the amount of improvement was related to the baseline-aided ANL value.


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.


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