Audiovisual speech is more than the sum of its parts: Auditory-visual superadditivity compensates for age-related declines in audible and lipread speech intelligibility

Importance of Visual Support Through Lipreading in the Identification of Words in Spanish Language

We sought to examine the contribution of visual cues, such as lipreading, in the identification of familiar (words) and unfamiliar (phonemes) words in terms of percent accuracy. For that purpose, in this retrospective study, we presented lists of words and phonemes (adult female healthy voice) in auditory (A) and audiovisual (AV) modalities to 65 Spanish normal-hearing male and female listeners classified in four age groups. Our results showed a remarkable benefit of AV information in word and phoneme recognition. Regarding gender, women exhibited better performance than men in both A and AV modalities, although we only found significant differences for words but not for phonemes. Concerning age, significant differences were detected in word recognition in the A modality between the youngest (18-29 years old) and oldest (⩾50 years old) groups only. We conclude visual information enhances word and phoneme recognition and women are more influenced by visual signals than men in AV speech perception. On the contrary, it seems that, overall, age is not a limiting factor for word recognition, with no significant differences observed in the AV modality.

Virtual Staff Training to Support Communication for Older Adults With Untreated Hearing Loss in Care Settings

PURPOSE

The current quasi-experimental study aimed to develop and evaluate a virtual staff training on age-related hearing loss at a care organization for older adults.

METHOD

Training included the use of affordable headset amplifiers and a hands-on activity in which hearing loss was simulated. Staff were encouraged to offer amplifiers to assist in communication given the high prevalence of untreated hearing loss among older adults and the increased communication difficulty that results from mask-wearing.

RESULTS

Quantitative results (N = 51) from the pre/post questionnaire suggest that staff members gained knowledge about hearing loss and communication through the training session. Qualitative data over the 6-month post training suggest that some older adults had not only improved speech understanding but also improved quality of interactions with staff. The main reasons for not using the amplifiers were that staff would forget they had access to the amplifiers or the older adult would refuse to use the device.

CONCLUSION

This article highlights successes of the training as well as ideas for future trainings suggested by staff members. A key finding was the need to identify a core group of staff members who would be charged with facilitating use of personal amplification for older adults in the organization. In addition, providing multiple brief trainings over time was suggested to improve adoption of good communication practices among staff. [Journal of Gerontological Nursing, 50(4), 48-56.].

Stimulus Onset Asynchrony Affects Weighting-related Event-related Spectral Power in Self-motion Perception

Self-motion perception relies primarily on the integration of the visual, vestibular, proprioceptive, and somatosensory systems. There is a gap in understanding how a temporal lag between visual and vestibular motion cues affects visual-vestibular weighting during self-motion perception. The beta band is an index of visual-vestibular weighting, in that robust beta event-related synchronization (ERS) is associated with visual weighting bias, and robust beta event-related desynchronization is associated with vestibular weighting bias. The present study examined modulation of event-related spectral power during a heading judgment task in which participants attended to either visual (optic flow) or physical (inertial cues stimulating the vestibular, proprioceptive and somatosensory systems) motion cues from a motion simulator mounted on a MOOG Stewart Platform. The temporal lag between the onset of visual and physical motion cues was manipulated to produce three lag conditions: simultaneous onset, visual before physical motion onset, and physical before visual motion onset. There were two main findings. First, we demonstrated that when the attended motion cue was presented before an ignored cue, the power of beta associated with the attended modality was greater than when visual-vestibular cues were presented simultaneously or when the ignored cue was presented first. This was the case for beta ERS when the visual-motion cue was attended to, and beta event-related desynchronization when the physical-motion cue was attended to. Second, we tested whether the power of feature-binding gamma ERS (demonstrated in audiovisual and visual-tactile integration studies) increased when the visual-vestibular cues were presented simultaneously versus with temporal asynchrony. We did not observe an increase in gamma ERS when cues were presented simultaneously, suggesting that electrophysiological markers of visual-vestibular binding differ from markers of audiovisual and visual-tactile integration. All event-related spectral power reported in this study were generated from dipoles projecting from the left and right motor areas, based on the results of Measure Projection Analysis.

Increases in sensory noise predict attentional disruptions to audiovisual speech perception

We receive information about the world around us from multiple senses which combine in a process known as multisensory integration. Multisensory integration has been shown to be dependent on attention; however, the neural mechanisms underlying this effect are poorly understood. The current study investigates whether changes in sensory noise explain the effect of attention on multisensory integration and whether attentional modulations to multisensory integration occur via modality-specific mechanisms. A task based on the McGurk Illusion was used to measure multisensory integration while attention was manipulated via a concurrent auditory or visual task. Sensory noise was measured within modality based on variability in unisensory performance and was used to predict attentional changes to McGurk perception. Consistent with previous studies, reports of the McGurk illusion decreased when accompanied with a secondary task; however, this effect was stronger for the secondary visual (as opposed to auditory) task. While auditory noise was not influenced by either secondary task, visual noise increased with the addition of the secondary visual task specifically. Interestingly, visual noise accounted for significant variability in attentional disruptions to the McGurk illusion. Overall, these results strongly suggest that sensory noise may underlie attentional alterations to multisensory integration in a modality-specific manner. Future studies are needed to determine whether this finding generalizes to other types of multisensory integration and attentional manipulations. This line of research may inform future studies of attentional alterations to sensory processing in neurological disorders, such as Schizophrenia, Autism, and ADHD.

Neural correlates of multisensory enhancement in audiovisual narrative speech perception: a fMRI investigation

This fMRI study investigated the effect of seeing articulatory movements of a speaker while listening to a naturalistic narrative stimulus. It had the goal to identify regions of the language network showing multisensory enhancement under synchronous audiovisual conditions. We expected this enhancement to emerge in regions known to underlie the integration of auditory and visual information such as the posterior superior temporal gyrus as well as parts of the broader language network, including the semantic system. To this end we presented 53 participants with a continuous narration of a story in auditory alone, visual alone, and both synchronous and asynchronous audiovisual speech conditions while recording brain activity using BOLD fMRI. We found multisensory enhancement in an extensive network of regions underlying multisensory integration and parts of the semantic network as well as extralinguistic regions not usually associated with multisensory integration, namely the primary visual cortex and the bilateral amygdala. Analysis also revealed involvement of thalamic brain regions along the visual and auditory pathways more commonly associated with early sensory processing. We conclude that under natural listening conditions, multisensory enhancement not only involves sites of multisensory integration but many regions of the wider semantic network and includes regions associated with extralinguistic sensory, perceptual and cognitive processing.

Costs and benefits of audiovisual interactions

A strong temporal correlation promotes integration of concurrent sensory signals, either within a single sensory modality, or from different modalities. Although the benefits of such integration are well known, far less attention has been given to possible costs incurred when concurrent sensory signals are uncorrelated. In two experiments, subjects categorized the rate at which a visual object modulated in size, while they also tried to ignore a concurrent task-irrelevant broadband sound. Overall, the experiments showed that (i) losses in accuracy from mismatched auditory and visual rates were larger than gains from matched rates and (ii) mismatched auditory and visual rates slowed responses more than they were sped up when rates matched. Experiment One showed that audiovisual interaction varied with the difference between the visual modulation rate and the modulation rate of a concurrent auditory stimulus. Experiment Two showed that audiovisual interaction depended upon the strength of the task-irrelevant auditory modulation. Although our stimuli involved abstract, low-dimensional stimuli, not speech, the effects we observed parallel key findings on interference in multi-speaker settings.

Sensory Perception Mechanism for Preparing the Combinations of Stimuli Operation in the Architectural Experience

Sensory stimuli in an architectural space play an important role in the human perception of the indoor environment, no matter whether they are static or dynamic, isolated, or combined. By enhancing some perceptions in the sensory stimuli, the overall perceptions of an architectural space can be improved, especially for an intelligent architectural space. As yet, there are few studies reported about the sensory perception mechanism for the sensory stimuli operation in the architectural experience. In this research, a wooden micro building was prepared for the study of the sensitivity level of participants to various sensory stimuli in the same and in different sensory domains. Participants’ visual, auditory, olfactory, tactile and kinaesthesia perceptions were discussed statistically in terms of the sensitivity level. Based on the study, the effect of a single dynamic sensory stimulus (a dynamically coloured light) on the participants’ perception was studied in a paper architectural model from two aspects including preference and emotion. The dynamically coloured light was discussed statistically in terms of the level of preference. The study showed that there are significant differences among participants’ levels of sensitivity to the different sensory domains and to the different sensory stimuli. In particular, the sensitivity level to the stimulus that is the colour of a space is the highest of all stimuli. As a single changing sensory stimulus, a dynamically coloured light can lead to significant mood fluctuations and changes in the preference level. In particular, yellow is the favourite colour of light. The object of this study is expected to provide a theoretical foundation that is related to sensory choice, sensory perception enhancement and the combination forms of sensory perceptions. Based on the theoretical foundation, the perception design of overlapped multi-sensory stimuli and a single dynamic stimulus can be conducted to improve the quality of the indoor environment of normal and intelligent multi-sensory architecture.

Lipreading: A Review of Its Continuing Importance for Speech Recognition With an Acquired Hearing Loss and Possibilities for Effective Training

PURPOSE

The goal of this review article is to reinvigorate interest in lipreading and lipreading training for adults with acquired hearing loss. Most adults benefit from being able to see the talker when speech is degraded; however, the effect size is related to their lipreading ability, which is typically poor in adults who have experienced normal hearing through most of their lives. Lipreading training has been viewed as a possible avenue for rehabilitation of adults with an acquired hearing loss, but most training approaches have not been particularly successful. Here, we describe lipreading and theoretically motivated approaches to its training, as well as examples of successful training paradigms. We discuss some extensions to auditory-only (AO) and audiovisual (AV) speech recognition.

METHOD

Visual speech perception and word recognition are described. Traditional and contemporary views of training and perceptual learning are outlined. We focus on the roles of external and internal feedback and the training task in perceptual learning, and we describe results of lipreading training experiments.

RESULTS

Lipreading is commonly characterized as limited to viseme perception. However, evidence demonstrates subvisemic perception of visual phonetic information. Lipreading words also relies on lexical constraints, not unlike auditory spoken word recognition. Lipreading has been shown to be difficult to improve through training, but under specific feedback and task conditions, training can be successful, and learning can generalize to untrained materials, including AV sentence stimuli in noise. The results on lipreading have implications for AO and AV training and for use of acoustically processed speech in face-to-face communication.

CONCLUSION

Given its importance for speech recognition with a hearing loss, we suggest that the research and clinical communities integrate lipreading in their efforts to improve speech recognition in adults with acquired hearing loss.

Early auditory cortical processing predicts auditory speech in noise identification and lipreading

Individuals typically exhibit better cross-sensory perception following unisensory loss, demonstrating improved perception of information available from the remaining senses and increased cross-sensory use of neural resources. Even individuals with no sensory loss will exhibit such changes in cross-sensory processing following temporary sensory deprivation, suggesting that the brain's capacity for recruiting cross-sensory sources to compensate for degraded unisensory input is a general characteristic of the perceptual process. Many studies have investigated how auditory and visual neural structures respond to within- and cross-sensory input. However, little attention has been given to how general auditory and visual neural processing relates to within and cross-sensory perception. The current investigation examines the extent to which individual differences in general auditory neural processing accounts for variability in auditory, visual, and audiovisual speech perception in a sample of young healthy adults. Auditory neural processing was assessed using a simple click stimulus. We found that individuals with a smaller P1 peak amplitude in their auditory-evoked potential (AEP) had more difficulty identifying speech sounds in difficult listening conditions, but were better lipreaders. The results suggest that individual differences in the auditory neural processing of healthy adults can account for variability in the perception of information available from the auditory and visual modalities, similar to the cross-sensory perceptual compensation observed in individuals with sensory loss.