Comparison of informational vs. energetic masking effects on speechreading performance

A Transparent Mask and Clear Speech Benefit Speech Intelligibility in Individuals With Hearing Loss

PURPOSE

The purpose of the study is to investigate the impacts of a surgical mask and a transparent mask on audio-only and audiovisual speech intelligibility in noise (i.e., 0 dB signal-to-noise ratio) in individuals with mild-to-profound hearing loss. The study also examined if individuals with hearing loss can benefit from using a transparent mask and clear speech for speech understanding in noise.

METHOD

Thirty-one individuals with hearing loss (from 22 to 74 years old) completed keyword identification tasks to measure face-masked speech intelligibility in noise. A mixed-effects logistic regression model was used to examine the effects of face masks (no mask, transparent mask, surgical mask), presentation modes (audio only, audiovisual), speaking styles (conversational, clear), noise type (speech-shaped noise [SSN], four-talker babble [4-T babble]), hearing groups (mild hearing loss [MHL], greater than MHL: GHL), and their interactions on binary accuracy of keyword identification.

RESULTS

In the audio-only mode, the GHL group showed reduced speech intelligibility regardless of other factors, whereas the MHL group showed decreased speech intelligibility for the transparent mask more than for the surgical mask. The use of a transparent mask was advantageous for both hearing loss groups. Clear speech remediated the detrimental effects of face masks on speech intelligibility in noise. Both groups tended to perform better in SSN versus 4-T babble.

CONCLUSIONS

The findings indicate that, when using face masks, either a transparent mask or a surgical mask negatively affects speech understanding in noise for individuals with hearing loss. Using a transparent mask and clear speech could be a potential solution to improve speech intelligibility in communication with face masks in noise.

The Impact of Personal Protective Equipment on Speech Discrimination and Verbal Communication in the Operating Room and the Role of Audio Communication Devices

INTRODUCTION

Recent work has highlighted communication difficulties when wearing personal protective equipment (PPE) in the clinical setting, but currently, there are little objective data on its effects. We assessed the impact of PPE on verbal communication in a simulated operating room and evaluated use of an audio communication device.

METHODOLOGY

Frontline health professionals across specialties including surgery, anesthetics, and nursing undertook speech discrimination testing with and without standardized levels of PPE in a simulated operating room environment. Background noise (30- and 70-a-weighted decibel multitalker babble) at 2 distances (2 and 4 m) were selected representative of operating room environments. Bamford-Kowal-Bench (BKB) scoring (192 sentences per participant) was performed. A Digital Multichannel Transceiver System (DMTS) was evaluated. We assessed the effects of PPE use, distance, and use of the DMTS with pairwise comparisons, using a Bonferroni correction, and assessed participant experience via Likert scales.

RESULTS

Thirty-one healthcare professionals were tested. Without PPE in 70-a-weighted decibel "babble," median BKB sentence scores were 90% and 76% at 2 and 4 m (adjusted P < 0.0005). The median BKB sentence scores dropped to 8% and 4% at 2 and 4 m in PPE (adjusted P < 0.0005). Improved speech discrimination was achieved with DMTS use to 70% and 76% at 2 and 4 m. Personal protective equipment led to a statistically significant reduction in BKB scores across all conditions compared with baseline. Overall participant confidence in PPE clinical communication was low.

CONCLUSIONS

Addition of PPE dramatically impairs speech discrimination and communication in high levels of background noise characteristic of clinical environments, which can be significantly improved using DMTS. Measures should be taken by teams through both through reduction of background noise and consideration of assistive technologies maximizing patient safety. This may be further rehearsed in a simulation environment.

Revisiting the target-masker linguistic similarity hypothesis

The linguistic similarity hypothesis states that it is more difficult to segregate target and masker speech when they are linguistically similar. For example, recognition of English target speech should be more impaired by the presence of Dutch masking speech than Mandarin masking speech because Dutch and English are more linguistically similar than Mandarin and English. Across four experiments, English target speech was consistently recognized more poorly when presented in English masking speech than in silence, speech-shaped noise, or an unintelligible masker (i.e., Dutch or Mandarin). However, we found no evidence for graded masking effects-Dutch did not impair performance more than Mandarin in any experiment, despite 650 participants being tested. This general pattern was consistent when using both a cross-modal paradigm (in which target speech was lipread and maskers were presented aurally; Experiments 1a and 1b) and an auditory-only paradigm (in which both the targets and maskers were presented aurally; Experiments 2a and 2b). These findings suggest that the linguistic similarity hypothesis should be refined to reflect the existing evidence: There is greater release from masking when the masker language differs from the target speech than when it is the same as the target speech. However, evidence that unintelligible maskers impair speech identification to a greater extent when they are more linguistically similar to the target language remains elusive.

Efficacy of the Digit-in-Noise Test: A Systematic Review and Meta-Analysis

Background and Objectives

Although the digit-in-noise (DIN) test is simple and quick, little is known about its key factors. This study explored the considerable components of the DIN test through a systematic review and meta-analysis.

Materials and Methods

After six electronic journal databases were screened, 14 studies were selected. For the meta-analysis, standardized mean difference was used to calculate effect sizes and 95% confidence intervals.

Results

The overall result of the meta-analysis showed an effect size of 2.224. In a subgroup analysis, the patient’s hearing status was found to have the highest effect size, meaning that the DIN test was significantly sensitive to screen for hearing loss. In terms of the length of the presenting digits, triple digits had lower speech recognition thresholds (SRTs) than single or pairs of digits. Among the types of background noise, speech-spectrum noise provided lower SRTs than multi-talker babbling. Regarding language variance, the DIN test showed better performance in the patient’s native language(s) than in other languages.

Conclusions

When uniformly developed and well validated, the DIN test can be a universal tool for hearing screening.

A comparison of simultaneously-obtained measures of listening effort: pupil dilation, verbal response time and self-rating

OBJECTIVE

The aim of this study was to assess to what extent simultaneously-obtained measures of listening effort (task-evoked pupil dilation, verbal response time [RT], and self-rating) could be sensitive to auditory and cognitive manipulations in a speech perception task. The study also aimed to explore the possible relationship between RT and pupil dilation.

DESIGN

A within-group design was adopted. All participants were administered the Matrix Sentence Test in 12 conditions (signal-to-noise ratios [SNR] of -3, -6, -9 dB; attentional resources focussed vs divided; spatial priors present vs absent).

STUDY SAMPLE

Twenty-four normal-hearing adults, 20-41 years old (M = 23.5), were recruited in the study.

RESULTS

A significant effect of the SNR was found for all measures. However, pupil dilation discriminated only partially between the SNRs. Neither of the cognitive manipulations were effective in modulating the measures. No relationship emerged between pupil dilation, RT and self-ratings.

CONCLUSIONS

RT, pupil dilation, and self-ratings can be obtained simultaneously when administering speech perception tasks, even though some limitations remain related to the absence of a retention period after the listening phase. The sensitivity of the three measures to changes in the auditory environment differs. RTs and self-ratings proved most sensitive to changes in SNR.

Auditory Pattern Representations Under Conditions of Uncertainty-An ERP Study

The auditory system is able to recognize auditory objects and is thought to form predictive models of them even though the acoustic information arriving at our ears is often imperfect, intermixed, or distorted. We investigated implicit regularity extraction for acoustically intact versus disrupted six-tone sound patterns via event-related potentials (ERPs). In an exact-repetition condition, identical patterns were repeated; in two distorted-repetition conditions, one randomly chosen segment in each sound pattern was replaced either by white noise or by a wrong pitch. In a roving-standard paradigm, sound patterns were repeated 1-12 times (standards) in a row before a new pattern (deviant) occurred. The participants were not informed about the roving rule and had to detect rarely occurring loudness changes. Behavioral detectability of pattern changes was assessed in a subsequent behavioral task. Pattern changes (standard vs. deviant) elicited mismatch negativity (MMN) and P3a, and were behaviorally detected above the chance level in all conditions, suggesting that the auditory system extracts regularities despite distortions in the acoustic input. However, MMN and P3a amplitude were decreased by distortions. At the level of MMN, both types of distortions caused similar impairments, suggesting that auditory regularity extraction is largely determined by the stimulus statistics of matching information. At the level of P3a, wrong-pitch distortions caused larger decreases than white-noise distortions. Wrong-pitch distortions likely prevented the engagement of restoration mechanisms and the segregation of disrupted from true pattern segments, causing stronger informational interference with the relevant pattern information.

Processing of Degraded Speech in Brain Disorders

The speech we hear every day is typically "degraded" by competing sounds and the idiosyncratic vocal characteristics of individual speakers. While the comprehension of "degraded" speech is normally automatic, it depends on dynamic and adaptive processing across distributed neural networks. This presents the brain with an immense computational challenge, making degraded speech processing vulnerable to a range of brain disorders. Therefore, it is likely to be a sensitive marker of neural circuit dysfunction and an index of retained neural plasticity. Considering experimental methods for studying degraded speech and factors that affect its processing in healthy individuals, we review the evidence for altered degraded speech processing in major neurodegenerative diseases, traumatic brain injury and stroke. We develop a predictive coding framework for understanding deficits of degraded speech processing in these disorders, focussing on the "language-led dementias"-the primary progressive aphasias. We conclude by considering prospects for using degraded speech as a probe of language network pathophysiology, a diagnostic tool and a target for therapeutic intervention.

Extending the study of visual attention to a multisensory world (Charles W. Eriksen Special Issue)

Charles W. Eriksen (1923-2018), long-time editor of Perception & Psychophysics (1971-1993) - the precursor to the present journal - undoubtedly made a profound contribution to the study of selective attention in the visual modality. Working primarily with neurologically normal adults, his early research provided both theoretical accounts for behavioral phenomena as well as robust experimental tasks, including the well-known Eriksen flanker task. The latter paradigm has been used and adapted by many researchers over the subsequent decades. While Eriksen's research interests were primarily focused on situations of unimodal visual spatially selective attention, here I review evidence from those studies that have attempted to extend Eriksen's general approach to non-visual (i.e., auditory and tactile) selection and the more realistic situations of multisensory spatial attentional selection.

What Can Computational Models Learn From Human Selective Attention? A Review From an Audiovisual Unimodal and Crossmodal Perspective

Selective attention plays an essential role in information acquisition and utilization from the environment. In the past 50 years, research on selective attention has been a central topic in cognitive science. Compared with unimodal studies, crossmodal studies are more complex but necessary to solve real-world challenges in both human experiments and computational modeling. Although an increasing number of findings on crossmodal selective attention have shed light on humans' behavioral patterns and neural underpinnings, a much better understanding is still necessary to yield the same benefit for intelligent computational agents. This article reviews studies of selective attention in unimodal visual and auditory and crossmodal audiovisual setups from the multidisciplinary perspectives of psychology and cognitive neuroscience, and evaluates different ways to simulate analogous mechanisms in computational models and robotics. We discuss the gaps between these fields in this interdisciplinary review and provide insights about how to use psychological findings and theories in artificial intelligence from different perspectives.

The effects of auditory spatial training on informational masking release in elderly listeners: a study protocol for a randomized clinical trial

Background: Regarding the strong auditory spatial plasticity capability of the central auditory system and the effect of short-term and long-term rehabilitation programs in elderly people, it seems that an auditory spatial training can help this population in informational masking release and better track speech in noisy environments. The main purposes of this study are developing an informational masking measurement test and an auditory spatial training program. Protocol: This study will be conducted in two parts. Part 1: develop and determine the validity of an informational masking measurement test by recruiting two groups of young (n=50) and old (n=50) participants with normal hearing who have no difficulty in understanding speech in noisy environments. Part 2 (clinical trial): two groups of 60-75-year-olds with normal hearing, who complain about difficulty in speech perception in noisy environments, will participate as control and intervention groups to examine the effect of auditory spatial training. Intervention: 8 sessions of auditory spatial training. The informational masking measurement test and Speech, Spatial and Qualities of Hearing Scale will be compared before intervention, immediately after intervention, and one month after intervention between the two groups. Discussion: Since auditory training programs do not deal with informational masking release, an auditory spatial training will be designed, aiming to improve hearing in noisy environments for elderly populations. Trial registration: Iranian Registry of Clinical Trials ( IRCT20190118042404N1) on 25 th February 2019.

The effects of auditory spatial training on informational masking release in elderly listeners: a study protocol for a randomized clinical trial

Background: Regarding the strong auditory spatial plasticity capability of the central auditory system and the effect of short-term and long-term rehabilitation programs in elderly people, it seems that an auditory spatial training can help this population in informational masking release and better track speech in noisy environments. The main purposes of this study are developing an informational masking measurement test and an auditory spatial training program. Protocol: This study will be conducted in two parts. Part 1: develop and determine the validity of an informational masking measurement test by recruiting two groups of young (n=50) and old (n=50) participants with normal hearing who have no difficulty in understanding speech in noisy environments. Part 2 (clinical trial): two groups of 60-75-year-olds with normal hearing, who complain about difficulty in speech perception in noisy environments, will participate as control and intervention groups to examine the effect of auditory spatial training. Intervention: 15 sessions of auditory spatial training. The informational masking measurement test and Speech, Spatial and Qualities of Hearing Scale will be compared before intervention, immediately after intervention, and five weeks after intervention between the two groups. Discussion: Since auditory training programs do not deal with informational masking release, an auditory spatial training will be designed, aiming to improve hearing in noisy environments for elderly populations. Trial registration: Iranian Registry of Clinical Trials ( IRCT20190118042404N1) on 25 th February 2019.