scholarly journals Speech Intelligibility and Spatial Release From Masking Improvements Using Spatial Noise Reduction Algorithms in Bimodal Cochlear Implant Users

2021 ◽  
Vol 25 ◽  
pp. 233121652110059
Author(s):  
Ayham Zedan ◽  
Tim Jürgens ◽  
Ben Williges ◽  
Birger Kollmeier ◽  
Konstantin Wiebe ◽  
...  

This study investigated the speech intelligibility benefit of using two different spatial noise reduction algorithms in cochlear implant (CI) users who use a hearing aid (HA) on the contralateral side (bimodal CI users). The study controlled for head movements by using head-related impulse responses to simulate a realistic cafeteria scenario and controlled for HA and CI manufacturer differences by using the master hearing aid platform (MHA) to apply both hearing loss compensation and the noise reduction algorithms (beamformers). Ten bimodal CI users with moderate to severe hearing loss contralateral to their CI participated in the study, and data from nine listeners were included in the data analysis. The beamformers evaluated were the adaptive differential microphones (ADM) implemented independently on each side of the listener and the (binaurally implemented) minimum variance distortionless response (MVDR). For frontal speech and stationary noise from either left or right, an improvement (reduction) of the speech reception threshold of 5.4 dB and 5.5 dB was observed using the ADM, and 6.4 dB and 7.0 dB using the MVDR, respectively. As expected, no improvement was observed for either algorithm for colocated speech and noise. In a 20-talker babble noise scenario, the benefit observed was 3.5 dB for ADM and 7.5 dB for MVDR. The binaural MVDR algorithm outperformed the bilaterally applied monaural ADM. These results encourage the use of beamformer algorithms such as the ADM and MVDR by bimodal CI users in everyday life scenarios.

2020 ◽  
Vol 24 ◽  
pp. 233121652091957
Author(s):  
Nico Gößling ◽  
Daniel Marquardt ◽  
Simon Doclo

Besides improving speech intelligibility in background noise, another important objective of noise reduction algorithms for binaural hearing devices is preserving the spatial impression for the listener. In this study, we evaluate the performance of several recently proposed noise reduction algorithms based on the binaural minimum-variance-distortionless-response (MVDR) beamformer, which trade-off between noise reduction performance and preservation of the interaural coherence (IC) for diffuse noise fields. Aiming at a perceptually optimized result, this trade-off is determined based on the IC discrimination ability of the human auditory system. The algorithms are evaluated with normal-hearing participants for an anechoic scenario and a reverberant cafeteria scenario, in terms of both speech intelligibility using a matrix sentence test and spatial quality using a MUlti Stimulus test with Hidden Reference and Anchor (MUSHRA). The results show that all the binaural noise reduction algorithms are able to improve speech intelligibility compared with the unprocessed microphone signals, where partially preserving the IC of the diffuse noise field leads to a significant improvement in perceived spatial quality compared with the binaural MVDR beamformer while hardly affecting speech intelligibility.


2020 ◽  
Author(s):  
Lieber Po-Hung Li ◽  
Ji-Yan Han ◽  
Wei-Zhong Zheng ◽  
Ren-Jie Huang ◽  
Ying-Hui Lai

BACKGROUND The cochlear implant technology is a well-known approach to help deaf patients hear speech again. It can improve speech intelligibility in quiet conditions; however, it still has room for improvement in noisy conditions. More recently, it has been proven that deep learning–based noise reduction (NR), such as noise classification and deep denoising autoencoder (NC+DDAE), can benefit the intelligibility performance of patients with cochlear implants compared to classical noise reduction algorithms. OBJECTIVE Following the successful implementation of the NC+DDAE model in our previous study, this study aimed to (1) propose an advanced noise reduction system using knowledge transfer technology, called NC+DDAE_T, (2) examine the proposed NC+DDAE_T noise reduction system using objective evaluations and subjective listening tests, and (3) investigate which layer substitution of the knowledge transfer technology in the NC+DDAE_T noise reduction system provides the best outcome. METHODS The knowledge transfer technology was adopted to reduce the number of parameters of the NC+DDAE_T compared with the NC+DDAE. We investigated which layer should be substituted using short-time objective intelligibility (STOI) and perceptual evaluation of speech quality (PESQ) scores, as well as t-distributed stochastic neighbor embedding to visualize the features in each model layer. Moreover, we enrolled ten cochlear implant users for listening tests to evaluate the benefits of the newly developed NC+DDAE_T. RESULTS The experimental results showed that substituting the middle layer (ie, the second layer in this study) of the noise-independent DDAE (NI-DDAE) model achieved the best performance gain regarding STOI and PESQ scores. Therefore, the parameters of layer three in the NI-DDAE were chosen to be replaced, thereby establishing the NC+DDAE_T. Both objective and listening test results showed that the proposed NC+DDAE_T noise reduction system achieved similar performances compared with the previous NC+DDAE in several noisy test conditions. However, the proposed NC+DDAE_T only needs a quarter of the number of parameters compared to the NC+DDAE. CONCLUSIONS This study demonstrated that knowledge transfer technology can help to reduce the number of parameters in an NC+DDAE while keeping similar performance rates. This suggests that the proposed NC+DDAE_T model may reduce the implementation costs of this noise reduction system and provide more benefits for cochlear implant users.


Author(s):  
Isiaka Ajewale Alimi

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.


2019 ◽  
Vol 40 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Arlene C. Neuman ◽  
Annette Zeman ◽  
Jonathan Neukam ◽  
Binhuan Wang ◽  
Mario A. Svirsky

2008 ◽  
Vol 123 (5) ◽  
pp. 555-557 ◽  
Author(s):  
J M Bernstein ◽  
P Z Sheehan

AbstractObjective:Bone-anchored hearing aid surgery in younger children is a two-stage procedure, with a titanium fixture being allowed to osseointegrate for several months before an abutment is fitted through a skin graft. In the first procedure, it has been usual to place a reserve or sleeper fixture approximately 5 mm from the primary fixture as a backup in case the primary fixture fails to osseointegrate. This ipsilateral sleeper fixture is expensive, is often not used, and is placed in thinner calvarial bone where it is less likely to osseointegrate successfully. The authors have implanted the sleeper fixture on the contralateral side, with the additional objective of reducing the number of procedures for bilateral bone-anchored hearing aid implantation, providing a cost-effective use for the sleeper.Methods:The authors implanted the bone-anchored hearing aid sleeper fixture in the contralateral temporal bone instead of on the ipsilateral side in seven successive paediatric cases with bilateral conductive hearing loss requiring two-stage bone-anchored hearing aids, treated at the Royal Manchester Children's Hospital, UK.Results:The seven patients ranged in age from five to 15 years, with a mean age of 10 years; in addition, a 20-year-old with learning disability was also treated. In each case, the contralateral sleeper fixture was not needed as a backup fixture, but was used in four patients (57 per cent) as the basis for a second-side bone-anchored hearing aid.Conclusions:In children with bilateral conductive hearing loss, in whom a bilateral bone-anchored hearing aid is being considered and the second side is to be operated upon at a later date, we recommend placing the sleeper fixture on the contralateral side at the time of primary first-side surgery. Our technique provides a sleeper fixture located in an optimal position, where it also offers the option of use for a second-side bone-anchored hearing aid and reduces the number of procedures needed.


2020 ◽  
Vol 5 (1) ◽  
pp. 36-39
Author(s):  
Mariya Yu. Boboshko ◽  
Irina P. Berdnikova ◽  
Natalya V. Maltzeva

Objectives -to determine the normative data of sentence speech intelligibility in a free sound field and to estimate the applicability of the Russian Matrix Sentence test (RuMatrix) for assessment of the hearing aid fitting benefit. Material and methods. 10 people with normal hearing and 28 users of hearing aids with moderate to severe sensorineural hearing loss were involved in the study. RuMatrix test both in quiet and in noise was performed in a free sound field. All patients filled in the COSI questionnaire. Results. The hearing impaired patients were divided into two subgroups: the 1st with high and the 2nd with low hearing aid benefit, according to the COSI questionnaire. In the 1st subgroup, the threshold for the sentence intelligibility in quiet was 34.9 ± 6.4 dB SPL, and in noise -3.3 ± 1.4 dB SNR, in the 2nd subgroup 41.7 ± 11.5 dB SPL and 0.15 ± 3.45 dB SNR, respectively. The significant difference between the data of both subgroups and the norm was registered (p


2003 ◽  
Vol 67 (10) ◽  
pp. 1061-1067 ◽  
Author(s):  
Shoichiro Fukuda ◽  
Kunihiro Fukushima ◽  
Naomi Toida ◽  
Keiko Tsukamura ◽  
Yukihide Maeda ◽  
...  

2020 ◽  
Vol 31 (05) ◽  
pp. 354-362
Author(s):  
Paula Folkeard ◽  
Marlene Bagatto ◽  
Susan Scollie

Abstract Background Hearing aid prescriptive methods are a commonly recommended component of evidence-based preferred practice guidelines and are often implemented in the hearing aid programming software. Previous studies evaluating hearing aid manufacturers' software-derived fittings to prescriptions have shown significant deviations from targets. However, few such studies examined the accuracy of software-derived fittings for the Desired Sensation Level (DSL) v5.0 prescription. Purpose The purpose of this study was to evaluate the accuracy of software-derived fittings to the DSL v5.0 prescription, across a range of hearing aid brands, audiograms, and test levels. Research Design This study is a prospective chart review with simulated cases. Data Collection and Analysis A set of software-derived fittings were created for a six-month-old test case, across audiograms ranging from mild to profound. The aided output from each fitting was verified in the test box at 55-, 65-, 75-, and 90-dB SPL, and compared with DSL v5.0 child targets. The deviations from target across frequencies 250-6000 Hz were calculated, together with the root-mean-square error (RMSE) from target. The aided Speech Intelligibility Index (SII) values generated for the speech passages at 55- and 65-dB SPL were compared with published norms. Study Sample Thirteen behind-the-ear style hearing aids from eight manufacturers were tested. Results The amount of deviation per frequency was dependent on the test level and degree of hearing loss. Most software-derived fittings for mild-to-moderately severe hearing losses fell within ± 5 dB of the target for most frequencies. RMSE results revealed more than 84% of those hearing aid fittings for the mild-to-moderate hearing losses were within 5 dB at all test levels. Fittings for severe to profound hearing losses had the greatest deviation from target and RMSE. Aided SII values for the mild-to-moderate audiograms fell within the normative range for DSL pediatric fittings, although they fell within the lower portion of the distribution. For more severe losses, SII values for some hearing aids fell below the normative range. Conclusions In this study, use of the software-derived manufacturers' fittings based on the DSL v5.0 pediatric targets set most hearing aids within a clinically acceptable range around the prescribed target, particularly for mild-to-moderate hearing losses. However, it is likely that clinician adjustment based on verification of hearing aid output would be required to optimize the fit to target, maximize aided SII, and ensure appropriate audibility across all degrees of hearing loss.


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