Improve Speech Intelligibility Research Articles

Cochlear implant outcomes in the very elderly

PurposeManaging hearing health in older adults has become a public health imperative, and cochlear implantation is now the standard of care for aural rehabilitation when hearing aids no longer provide sufficient benefit. The aim of our study was to compare speech performance in cochlear implant patients ≥80 years of age (Very Elderly) to a younger elderly cohort between ages 65–79 years (Less Elderly). Materials and methodsData were collected from 53 patients ≥80 years of age and 92 patients age 65–79 years who underwent cochlear implantation by the senior author between April 1, 2017 and May 12, 2020. The primary outcome measure compared preoperative AzBio Quiet scores to 6-month post-activation AzBio Quiet results for both cohorts. ResultsVery Elderly patients progressed from an average AzBio Quiet score of 22% preoperatively to a score of 45% in the implanted ear at 6-months post-activation (p < 0.001) while the Less Elderly progressed from an average score of 27% preoperatively to 60% at 6-months (p < 0.001). Improvements in speech intelligibility were statistically significant within each of these cohorts (p < 0.001). Comparative statistics using independent samples t-test and evaluation of effect size using the Hedges' g statistic demonstrated a significant difference for average improvement of AzBio in quiet scores between groups with a medium effect size (p = 0.03, g = 0.35). However, when the very oldest patients (90+ years) were removed, the statistical difference between groups disappeared (p = 0.09). ConclusionsWhen assessing CI performance, those over age 65 are typically compared to younger patients; however, this manuscript further stratifies audiometric outcomes for older CI recipients in a single-surgeon, high-volume practice. Our data indicates that for speech intelligibility, patients between age 65–79 perform similarly to CI recipients 80–90 years of age and should not be dismissed as potential cochlear implant candidates.

Effects of urgent speech and congruent/incongruent text on speech intelligibility for older adults in the presence of noise and reverberation

Public address (PA) announcements are widely used, but noise and reverberation can render them unintelligible, and such an environment tends to degrade speech intelligibility more for older adults (OAs) than for younger adults (YAs). Furthermore, in an emergency, textual information available to the public may not coincide with PA announcements, and this mismatch may also contribute to degrading the intelligibility of the announcement. In this study, speech spoken in a normal or urgent style and preceded by congruent or incongruent text was presented to OA participants to investigate the effects of these parameters on word intelligibility in the presence of babble noise and reverberation. This study also investigated age-related differences between OAs and YAs using the same stimuli. The results showed that, while YAs performed better than OAs, the effect of urgent speech did not significantly differ with age. Urgent speech was more intelligible than normal speech, and the congruent text condition was more intelligible than the incongruent and no text conditions. An exploratory analysis showed that urgent speech improved speech intelligibility for OAs when congruent text was available, but not when absent or incongruent. Without congruent information, this listening test may have been too demanding for OAs, who could have had more difficulty processing the fixed timeline of the listening test, the faster urgent speech relative to normal speech, and informational masking because of the slowing of cognitive processing with age. A correlation was found between the average word correct rate for urgent speech and average audiometric thresholds; on the other hand, increased fundamental frequencies in urgent compared with normal speech was not the main predictor of the intelligibility of urgent speech among the OAs. The congruent text benefit in urgent speech was larger for OAs than for YAs in the previous study using the same stimuli. This demonstrates that compared with YAs, OAs may rely more on supportive prior knowledge or receive more benefit from the preceding text in challenging listening environments. These findings imply that age-related cognitive decline may explain the difficulties in speech perception in the presence of noise and reverberation among OAs; however, no definitive conclusions can be drawn. These results suggest that simple combinations of speaking style and textual information affect the intelligibility of emergency PA announcements among OAs, and thus, audiovisual congruence should be considered when announcements are made in public spaces.

Phase sensitive masking-based single channel speech enhancement using conditional generative adversarial network

We propose PSMGAN, an efficient phase sensitive masking-based single-channel speech enhancement technique using a conditional generative adversarial network (cGAN). The time–frequency (T-F) masking-based speech enhancement approaches through deep neural networks (DNNs) have shown large speech intelligibility improvements. However, these approaches fail to achieve better enhancement results at low signal-to-noise ratio (SNR) conditions since they ignore the phase information during reconstruction. Alternatively, GANs have been introduced effectively for speech enhancement and achieved improved performance due to the adversarial training. Motivated by the recent success of GAN, we introduce the phase sensitive masking (PSM) in a cGAN framework for speech enhancement task. The reason for choosing a conditional generative model is that the data generation process can be controlled with the use of additional temporal context information. In addition, we use gradient penalty regularization in the discriminator of the cGAN network to avoid vanishing gradients problem which in turn stabilizes the training of the cGAN network and increases the quality of the generated samples. The use of PSM is due to the fact that it involves both amplitude and phase information and produces an improved estimate of clean speech signal with higher SNR as compared to other T-F masks. Experimental results show the proposed PSM based cGAN architecture has shown significant improvements in performance measures compared to other baselines such as SEGAN, Deep Feature Loss, MetricGAN, AECNN, DNN-cIRM, and end-to-end approach with reference to quality and intelligibility.

Hearing Aid Technology to Improve Speech Intelligibility in Noise.

Understanding speech in noise is difficult for individuals with normal hearing and is even more so for individuals with hearing loss. Difficulty understanding speech in noise is one of the primary reasons people seek hearing assistance. Despite amplification, many hearing aid users still struggle to understand speech in noise. In response to this persistent problem, hearing aid manufacturers have invested significantly in developing new solutions. Any solution is not without its tradeoffs, and decisions must be made when optimizing and implementing them. Much of this happens behind the scenes, and casual observers fail to appreciate the nuances of developing new hearing aid technologies. The difficulty of communicating this information to clinicians may hinder the use or the fine-tuning of the various technologies available today. The purpose of this issue of Seminars in Hearing is to educate professionals and students in audiology, hearing science, and engineering about different approaches to combat problems related to environmental and wind noise using technologies that include classification, directional microphones, binaural signal processing, beamformers, motion sensors, and machine learning. To accomplish this purpose, some of the top researchers and engineers from the world's largest hearing aid manufacturers agreed to share their unique insights.

Binaural Signal Processing in Hearing Aids.

For many years, clinicians have understood the advantages of listening with two ears compared with one. In addition to improved speech intelligibility in quiet, noisy, and reverberant environments, binaural versus monaural listening improves perceived sound quality and decreases the effort listeners must expend to understand a target voice of interest or to monitor a multitude of potential target voices. For most individuals with bilateral hearing impairment, the body of evidence collected across decades of research has also found that the provision of two compared with one hearing aid yields significant benefit for the user. This article briefly summarizes the major advantages of binaural compared with monaural hearing, followed by a detailed description of the related technological advances in modern hearing aids. Aspects related to the communication and exchange of data between the left and right hearing aids are discussed together with typical algorithmic approaches implemented in modern hearing aids.

Increasing the Effectiveness of Hearing Aid Directional Microphones.

Directionality is the only hearing aid technology — in addition to amplification — proven to help hearing aid users hear better in noise. Hearing aid directionality has been documented to improve speech intelligibility in multiple laboratory studies. In contrast, real-world studies have shown a disconnect between the potential of the technology and what hearing aid users experience in their daily life. This article describes the real-world studies that inspired ReSound to take a different approach to applying directional microphone technology. This approach is based on the idea that hearing aid directionality can leverage natural binaural hearing and inherent listening strategies. The directional strategy includes three listening modes that will be explained. These are the Spatial Cue Preservation mode, the Binaural Listening mode, and the Speech Intelligibility mode. The strategy and the advantages it provides in terms of sound quality, spatial hearing, and improved signal-to-noise ratio with maintained awareness of surroundings are explained.

A state-of-the-art implementation of a binaural cochlear-implant sound coding strategy inspired by the medial olivocochlear reflex

Cochlear implant (CI) users find it hard and effortful to understand speech in noise with current devices. Binaural CI sound processing inspired by the contralateral medial olivocochlear (MOC) reflex (an approach termed the ‘MOC strategy’) can improve speech-in-noise recognition for CI users. All reported evaluations of this strategy, however, disregarded automatic gain control (AGC) and fine‐structure (FS) processing, two standard features in some current CI devices. To better assess the potential of implementing the MOC strategy in contemporary CIs, here, we compare intelligibility with and without MOC processing in combination with linked AGC and FS processing. Speech reception thresholds (SRTs) were compared for an FS and a MOC-FS strategy for sentences in steady and fluctuating noises, for various speech levels, in bilateral and unilateral listening modes, and for multiple spatial configurations of the speech and noise sources. Word recall scores and verbal response times in a word recognition test (two proxies for listening effort) were also compared for the two strategies in quiet and in steady noise at 5 dB signal-to-noise ratio (SNR) and the individual SRT. In steady noise, mean SRTs were always equal or better with the MOC-FS than with the standard FS strategy, both in bilateral (the mean and largest improvement across spatial configurations and speech levels were 0.8 and 2.2 dB, respectively) and unilateral listening (mean and largest improvement of 1.7 and 2.1 dB, respectively). In fluctuating noise and in bilateral listening, SRTs were equal for the two strategies. Word recall scores and verbal response times were not significantly affected by the test SNR or the processing strategy. Results show that MOC processing can be combined with linked AGC and FS processing. Compared to using FS processing alone, combined MOC-FS processing can improve speech intelligibility in noise without affecting word recall scores or verbal response times.

Speech Enhancement for Hearing Impaired Based on Bandpass Filters and a Compound Deep Denoising Autoencoder

Deep neural networks have been applied for speech enhancements efficiently. However, for large variations of speech patterns and noisy environments, an individual neural network with a fixed number of hidden layers causes strong interference, which can lead to a slow learning process, poor generalisation in an unknown signal-to-noise ratio in new inputs, and some residual noise in the enhanced output. In this paper, we present a new approach for the hearing impaired based on combining two stages: (1) a set of bandpass filters that split up the signal into eight separate bands each performing a frequency analysis of the speech signal; (2) multiple deep denoising autoencoder networks, with each working for a small specific enhancement task and learning to handle a subset of the whole training set. To evaluate the performance of the approach, the hearing-aid speech perception index, the hearing aid sound quality index, and the perceptual evaluation of speech quality were used. Improvements in speech quality and intelligibility were evaluated using seven subjects of sensorineural hearing loss audiogram. We compared the performance of the proposed approach with individual denoising autoencoder networks with three and five hidden layers. The experimental results showed that the proposed approach yielded higher quality and was more intelligible compared with three and five layers.

Effect of reverberation and noise type on speech intelligibility in real complex acoustic scenarios

Enhanced speech intelligibility in realistic acoustic scenarios guarantees effective communication. Noise and reverberation degrade speech intelligibility, but the combined effect of reverberation, informational noise and position of target, listener and noise source on speech intelligibility still needs to insights. This work investigates the effect of real complex acoustic scenarios on speech intelligibility for adults. In two primary-school classrooms with reverberation time of 0.4 s and 3.1 s, receivers were located on axis with the target at increasing distances, and noise sources were both co-located and spatially separated from the target at different distances providing various degrees of energetic and informational masking. Noise level was maintained constant and set at 60 dB at the receiver's position, regardless of the noise source distance. The longer reverberation time resulted in worse speech recognition thresholds (SRT80s) by 6 dB on average. The competitive effect of informational noise resulted in increased SRT80s by 7 dB on average, in comparison to energetic noise. The SRT80 increases by ~2 dB with doubling the target-to-receiver distance when the noise source is close to the receiver, accounting for both reverberations and noise types. The spatial release from masking resulted in improved speech intelligibility by up to ~3 dB when the noise source is 1 m far from the receiver for energetic masker for low reverberation and, unexpectedly, for the informational masker in high reverberation. This may indicate that a perceptual segregation mechanism sorts out competing voices of informational masker according to their directions in least favorable listening situations.

Effect of clear speech intervention program on speech intelligibility in persons with idiopathic Parkinson’s disease: A pilot study

Purpose: This preliminary study was designed to assess the feasibility of Clear Speech Intervention Program (CSIP) on improving speech intelligibility of persons with idiopathic Parkinson’s disease (PD). Clear Speech is a behavioural approach which focuses on improving speech intelligibility of persons with PD within a relatively short frame of time. Method: A single group pretest-posttest design was used to assess the effectiveness of CSIP. Fifteen adults diagnosed with PD participated in 8 sessions of CSIP with each session lasting 45–50 minutes over a period of 4 weeks in South Korea. All the data were collected in a quiet room with an ambient noise level of equal to or less than 40 dB SPL. Data on acoustical/aerodynamic, auditory-perceptual, and self-perceptual measures were obtained pre- and post-intervention. The Phonatory Aerodynamic System (PAS) was used to analyse acoustical/aerodynamic data. Result: The acoustical/aerodynamic assessment revealed statistically significant (p < 0.01) improvements in habitual pitch, pitch range, speaking rate, and number of respirations. In the auditory-perceptual assessment, statistically significant (p < 0.01) improvements were observed in overall speech intelligibility, tone, intonation, intensity, and articulation. Medium to large effect sizes were observed for significant results. The Pearson correlation analysis showed significant (p < 0.01) and strong correlation between articulation and speech intelligibility. Conclusion: The preliminary data has provided promising results and warrants future large-scale studies with suitable controls. Additionally, future research must focus on investigating long term effects of the intervention.

A Novel Protocol Designed to Treat Spastic Dysarthria Secondary to Traumatic Brain Injury: A Case Study

IntroductionSpastic dysarthria is a motor speech disorder produced by bilateral damage to the activation pathways of the central nervous system. Its speech characteristics reflect the effects of hypertonicity and weakness of the bulbar musculature in a way that slows movement and reduces range of motion and force. Perceptually, speech has a high-pitched, strained, hypernasal vocal quality with decreased intelligibility.PurposeThe purpose is to present a case illustration describing the use of a novel treatment protocol to improve speech intelligibility in the presence of spastic dysarthria.MethodAn underlying framework, including principles of exercise, neuroplasticity, and motor learning with adjunctive biofeedback, is described. The protocol consisted of four sessions per week for 4 weeks with daily homework.ResultsThe participant exhibited improvements in intelligibility, patient satisfaction, lingual, and jaw range of motion, nasality, and tongue strength.ConclusionThe use of a novel protocol using biofeedback and incorporating principles of exercise science, neuroplasticity, and motor learning for the treatment of spastic dysarthria demonstrated positive outcomes.

Effects of Visual Speech Envelope on Audiovisual Speech Perception in Multitalker Listening Environments.

Purpose This study investigated the effects of visually presented speech envelope information with various modulation rates and depths on audiovisual speech perception in noise. Method Forty adults (21.25 ± 1.45 years) participated in audiovisual sentence recognition measurements in noise. Target speech sentences were auditorily presented in multitalker babble noises at a -3 dB SNR. Acoustic amplitude envelopes of target signals were extracted through low-pass filters with different cutoff frequencies (4, 10, and 30 Hz) and a fixed modulation depth at 100% (Experiment 1) or extracted with various modulation depths (0%, 25%, 50%, 75%, and 100%) and a fixed 10-Hz modulation rate (Experiment 2). The extracted target envelopes were synchronized with the amplitude of a spherical-shaped ball and presented as visual stimuli. Subjects were instructed to attend to both auditory and visual stimuli of the target sentences and type down their answers. The sentence recognition accuracy was compared between audio-only and audiovisual conditions. Results In Experiment 1, a significant improvement in speech intelligibility was observed when the visual analog (a sphere) synced with the acoustic amplitude envelope modulated at a 10-Hz modulation rate compared to the audio-only condition. In Experiment 2, the visual analog with 75% modulation depth resulted in better audiovisual speech perception in noise compared to the other modulation depth conditions. Conclusion An abstract visual analog of acoustic amplitude envelopes can be efficiently delivered by the visual system and integrated online with auditory signals to enhance speech perception in noise, independent of particular articulation movements.

Is talker variability a critical component of effective phonetic training for nonnative speech?

The current investigation adopted high variability phonetic training with additional audiovisual input and adaptive acoustic exaggeration to examine the role of talker variability. Sixty native Chinese-speaking adults were randomly assigned to a multiple-talker (MT) training group, a single-talker (ST) training group, and a control (CTRL) group without training. The target sounds were the English /i/-/ɪ/ contrast, delivered in 7 sessions using minimal pair word lists. Pre- and post-tests employed natural word identification, synthetic phoneme identification, and word production. Unlike the CTRL group, both training groups showed significant identification improvements, and the effects generalized to novel talkers and new phonetic contexts. Although training did not improve speech intelligibility, there was a significant gain in the use of the primary spectral cues and a decrease in the secondary durational cue. No differences were observed between the MT and ST groups. By removing the “enhancement” features, however, the training program with independent samples was able to verify the advantages of MT over ST training. These results provide the first evidence for the efficacy of other facilitative training features, independent of talker variability, in retuning second language learners’ attention to critical acoustic cues for the target speech contrast and producing transfer of learning.

Deep brain stimulation fine-tuning in Parkinson's disease: Short pulse width effect on speech

Backgroundsubthalamic nucleus deep brain stimulation (STN-DBS) may have a detrimental effect on speech in Parkinson's disease (PD) patients and new stimulation technologies may help in addressing this issue. Objectiveto evaluate the STN-DBS acute effect of 30 μs pulse width (30PW) versus conventional 60 μs PW (60PW) on speech and identify the core features of voice modified by 30PW. Methodsseven STN-DBS treated PD patients participated into a pilot cross-sectional study. Motor and speech performances were tested by means of both automatic analysis and blinded clinical evaluations in four stimulation conditions: 30PW and 60PW both at the usual amplitude and at an amplitude just below the threshold for stimulation-related side effects. Resultsat the threshold amplitude, 30PW stimulation improved speech intelligibility for both words (p = 0.02) and sentences (p = 0.04), without worsening motor performance. A lower but not statistically significant voice variability and instability and percentage of stuttering disfluencies was also observed. The beneficial effect of 30PW detected by automatic analysis, was confirmed by patients’ perception. ConclusionsSTN-DBS treated patients experiencing low speech intelligibility may benefit from a 30PW stimulation trial at a higher amplitude. Deep characterization of PD speech profiles may help in a better application of recent DBS hardware advances.

Association of In-Ear Device Use With Communication Quality Among Individuals Wearing Personal Protective Equipment in a Simulated Operating Room

The COVID-19 pandemic has brought forth new challenges for health care workers, such as the daily use of personal protective equipment, including reusable facial respirators. Poor communication while wearing respirators may have fatal complications for patients, and no solution has been proposed to date. To examine whether use of an in-ear communication device is associated with improved communication while wearing different personal protective equipment (N95 mask, half-face elastomeric respirator, and powered air-purifying respirator [PAPR]) in the operating room. This quality improvement study was conducted in June 2020. Surgical residents from the Department of Otolaryngology-Head and Neck Surgery at McGill University in Montreal, Quebec, Canada, were recruited. All participants had normal hearing, were fluent in English, and had access to the operating rooms at the Royal Victoria Hospital. All participants performed the speech intelligibility tasks with and without an in-ear communication device. Speech intelligibility was measured using a word recognition task (Modified Rhyme Test) and a sentence recognition task (AzBio Sentence Test). A percentage correct score (0% to 100%) was obtained for each speech intelligibility test. Listening effort was assessed using the NASA Task Load Index. An overall workload score, ranging from 0 points (low workload) to 100 points (high workload), was obtained. A total of 12 participants were included (mean [SD] age, 31.2 [1.9] years; 8 women [66.7%]). AzBio Sentence Test results revealed that, while wearing the N95 mask, the mean (SD) speech intelligibility was 98.8% (1.8%) without the in-ear device vs 94.3% (7.4%) with the device. While wearing the half-face elastomeric respirator, the mean speech intelligibility was 58.5% (12.4%) without the in-ear device vs 90.8% (8.9%) with the device. While wearing the PAPR, the mean speech intelligibility was 84.6% (9.8%) without the in-ear device vs 94.5% (5.5%) with the device. Use of the in-ear device was associated with a significant improvement in speech intelligibility while wearing the half-face elastomeric respirator (32.3%; 95% CI, 23.8%-40.7%; P < .001) and the PAPR (9.9%; 95% CI, 1.4%-18.3%; P = .01). Furthermore, use of the device was associated with decreased listening effort. The NASA Task Load Index results reveal that, while wearing the N95 mask, the mean (SD) overall workload score was 12.6 (10.6) points without the in-ear device vs 17.6 (9.2) points with the device. While wearing the half-face elastomeric respirator, the mean overall workload score was 67.7 (21.6) points without the in-ear device vs 29.3 (14.4) points with the in-ear device. While wearing the PAPR, the mean overall workload score was 42.2 (18.2) points without the in-ear device vs 23.8 (12.8) points with the in-ear device. Use of the in-ear device was associated with a significant decrease in overall workload score while wearing the half-face elastomeric respirator (38.4; 95% CI, 23.5-53.3; P < .001) and the PAPR (18.4; 95% CI, 0.4-36.4; P = .04). This study found that among participants using facial respirators that impaired communication, a novel in-ear device was associated with improved communication and decreased listening effort. Such a device may be a feasible solution for protecting health care workers in the operating room while allowing them to communicate safely, especially during the COVID-19 pandemic.

Personalizing Transient Noise Reduction Algorithm Settings for Cochlear Implant Users.

Objectives:Speech understanding in noise is difficult for patients with a cochlear implant. One common and disruptive type of noise is transient noise. We have tested transient noise reduction (TNR) algorithms in cochlear implant users to investigate the merits of personalizing the noise reduction settings based on a subject’s own preference.Design:The effect of personalizing two parameters of a broadband and a multiband TNR algorithm (TNRbb and TNRmb, respectively) on speech recognition was tested in a group of 15 unilaterally implanted subjects in cafeteria noise. The noise consisted of a combination of clattering dishes and babble noise. Each participant could individually vary two parameters, namely the scaling factor of the attenuation and the release time (τ). The parameter τ represents the duration of the attenuation applied after a transient is detected. As a reference, the current clinical standard TNR “SoundRelax” from Advanced Bionics was tested (TNRbb-std). Effectiveness of the algorithms on speech recognition was evaluated adaptively by determining the speech reception threshold (SRT). Possible subjective benefits of the algorithms were assessed using a rating task at a fixed signal-to-noise ratio (SNR) of SRT + 3 dB. Rating was performed on four items, namely speech intelligibility, speech naturalness, listening effort, and annoyance of the noise. Word correct scores were determined at these fixed speech levels as well.Results:The personalized TNRmb improved the SRT statistically significantly with 1.3 dB, while the personalized TNRbb degraded it significantly by 1.7 dB. For TNRmb, we attempted to further optimize its settings by determining a group-based setting, leaving out those subjects that did not experience a benefit from it. Using these group-based settings, however, TNRmb did not have a significant effect on the SRT any longer. TNRbb-std did not affect speech recognition significantly. No significant effects on subjective ratings were found for any of the items investigated. In addition, at a constant speech level of SRT + 3 dB, no effect of any of the algorithms was found on word correct scores, including TNRmb with personalized settings.Conclusions:Our study results indicate that personalizing noise reduction settings of a multiband TNR algorithm can significantly improve speech intelligibility in transient noise, but only under challenging listening conditions around the SRT. At more favorable SNRs (SRT + 3 dB), this benefit was lost. We hypothesize that TNRmb was beneficial at lower SNRs, because of more effective artifact detection under those conditions. Group-averaged settings of the multiband algorithm did not significantly affect speech recognition. TNRbb decreased speech recognition significantly using personalized parameter settings. Rating scores were not significantly affected by the algorithms under any condition tested. The currently available TNR algorithm for Advanced Bionics systems (SoundRelax) is a broadband filter that does not support personalization of its settings. Future iterations of this algorithm might benefit from upgrading it to a multiband variant with the option to personalize its parameter settings.

Smart speaker devices can improve speech intelligibility in adults with intellectual disability.

Successful communication is vital to quality of life. One group commonly facing speech and communication difficulties is individuals with intellectual disability (ID). A novel route to encourage clear speech is offered by mainstream smart speakers (e.g., Amazon Alexa and Google Home). Smart speakers offer four factors important for learning: reward immediacy, spaced practice, autonomy/intrinsic motivation and reduced social barriers. Yet the potential of smart speakers to improve speech intelligibility has not been explored before. To determine whether providing individuals with intellectual disabilities with smart speaker devices improved ratings of speech intelligibility for (1) phrases related to device use and (2) unrelated words via a semi-randomized controlled trial. In a semi-randomized controlled trial, an intervention group of adults with ID (N = 21) received smart speakers, while a control group (N = 22) did not. Before and after about 12 weeks, participants were recorded saying smart speaker-related phrases and unrelated words. Naïve participants then rated the intelligibility of the speech recordings. The group that received smart speakers made significantly larger intelligibility gains than the control group. Although the effect size was modest, this difference was found for both smart speaker-related phrases and unrelated words. While the mechanism of action remains to be determined, the presence of smart speakers in the home had a demonstrable impact on ratings of speech intelligibility, and could provide cost-effective inclusive support for speech and communication improvement, improving the quality of life of vulnerable populations. What this paper adds What is already known on the subject Speech intelligibility is a key obstacle for social relationships and quality of life across several vulnerable populations (children with speech difficulties, older adults with dementia, individuals with ID). Anecdotal reports suggest mainstream smart speakers (e.g., Amazon Alexa, Google Home), could improve speech intelligibility. What this paper adds to existing knowledge We used a semi-randomized controlled trial to show that using a smart speaker for about 12 weeks could improve ratings of speech intelligibility in adults with ID for both smart speaker-related phrases and unrelated words. What are the potential or actual clinical implications of this work? These initial findings suggest that smart speaker technology could be a novel, and inclusive, route to improving speech intelligibility in vulnerable populations.

Speaker separation in realistic noise environments with applications to a cognitively-controlled hearing aid

Future wearable technology may provide for enhanced communication in noisy environments and for the ability to pick out a single talker of interest in a crowded room simply by the listener shifting their attentional focus. Such a system relies on two components, speaker separation and decoding the listener’s attention to acoustic streams in the environment. To address the former, we present a system for joint speaker separation and noise suppression, referred to as the Binaural Enhancement via Attention Masking Network (BEAMNET). The BEAMNET system is an end-to-end neural network architecture based on self-attention. Binaural input waveforms are mapped to a joint embedding space via a learned encoder, and separate multiplicative masking mechanisms are included for noise suppression and speaker separation. Pairs of output binaural waveforms are then synthesized using learned decoders, each capturing a separated speaker while maintaining spatial cues. A key contribution of BEAMNET is that the architecture contains a separation path, an enhancement path, and an autoencoder path. This paper proposes a novel loss function which simultaneously trains these paths, so that disabling the masking mechanisms during inference causes BEAMNET to reconstruct the input speech signals. This allows dynamic control of the level of suppression applied by BEAMNET via a minimum gain level, which is not possible in other state-of-the-art approaches to end-to-end speaker separation. This paper also proposes a perceptually-motivated waveform distance measure. Using objective speech quality metrics, the proposed system is demonstrated to perform well at separating two equal-energy talkers, even in high levels of background noise. Subjective testing shows an improvement in speech intelligibility across a range of noise levels, for signals with artificially added head-related transfer functions and background noise. Finally, when used as part of an auditory attention decoder (AAD) system using existing electroencephalogram (EEG) data, BEAMNET is found to maintain the decoding accuracy achieved with ideal speaker separation, even in severe acoustic conditions. These results suggest that this enhancement system is highly effective at decoding auditory attention in realistic noise environments, and could possibly lead to improved speech perception in a cognitively controlled hearing aid.

Modification of misarticulated fricative /s/ in cleft lip and palate speech

Cleft lip and palate is a craniofacial condition that affects the intelligibility of speech. The current work describes a modification of three types of misarticulated fricative /s/ in cleft lip and palate speech, which include palatalized /s/, phoneme-specific nasal air emission distorted /s/, and glottal stop substituted /s/. By using the knowledge of the glottal activity, frication, and silence, an approach is proposed for misarticulated fricative detection and categorization of the type of error. Based on the category of error, an appropriate modification technique is applied. The deviations of palatalized /s/ and phoneme-specific nasal air emission distorted /s/ are corrected by modifying the spectral energy. The high-frequency energy levels are emphasized to improve the perception of fricative /s/ using spectral tilt modification. Glottal stop substitution is modified by inserting artificially synthesized /s/, where the fricative /s/ signal is synthesized using white noise signal and linear prediction filter obtained from normal children fricative /s/. Further, the modified speech samples are subjected to objective and subjective evaluation. The evaluation scores obtained from objective and subjective assessment indicate speech intelligibility improvement of the modified signals compared to the misarticulated fricative /s/.

The effect of induction loop system use training on adults with hearing aids

The study aimed to investigate the effect of training on hearing aid users to benefit from induction loop systems. A five-question scale was developed to evaluate whether individuals using hearing aids could use the induction loop system effectively. In the first step, validity-reliability studies were performed with 264 individuals using hearing aids. In the second step, 30 individuals using hearing aids were given verbal and hands-on training on the induction loop system. Before and after training with hearing aids (noiseless, noise, noise + induction system active) in three different environments, questions on the scale were asked twice in total from the beginning to the end of the study. The significance of the differences between the values obtained as a result of the application of word lists in three different test settings was examined by repeating the measurements variance analysis. As a result of the post hoc analysis, P = 0.002 between test 3 (10.7, 1.53) and test 1 (11.7, 0.7) was calculated. There appears to be a statistically significant difference with the present situation (P < 0.01). The average scores of the scale between pre and posttraining applications as a preliminary and final test were analysed with a t-test. The final test average was statistically significantly greater than the preliminary test (P < 0.01). This study shows how important it is for hearing aid users to be informed and to receive the necessary training in order to gain the expected benefit from induction loop systems developed to improve speech intelligibility in noisy environments.