Brightening the Study of Listening Effort with Functional Near-Infrared Spectroscopy: A Scoping Review.

Listening effort is a long-standing area of interest in auditory cognitive neuroscience. Prior research has used multiple techniques to shed light on the neurophysiological mechanisms underlying listening during challenging conditions. Functional near-infrared spectroscopy (fNIRS) is growing in popularity as a tool for cognitive neuroscience research, and its recent advances offer many potential advantages over other neuroimaging modalities for research related to listening effort. This review introduces the basic science of fNIRS and its uses for auditory cognitive neuroscience. We also discuss its application in recently published studies on listening effort and consider future opportunities for studying effortful listening with fNIRS. After reading this article, the learner will know how fNIRS works and summarize its uses for listening effort research. The learner will also be able to apply this knowledge toward generation of future research in this area.

Developing a music-based digital therapeutic to help manage the neuropsychiatric symptoms of dementia.

The greying of the world is leading to a rapid acceleration in both the healthcare costs and caregiver burden that are associated with dementia. There is an urgent need to develop new, easily scalable modalities of support. This perspective paper presents the theoretical background, rationale, and development plans for a music-based digital therapeutic to manage the neuropsychiatric symptoms of dementia, particularly agitation and anxiety. We begin by presenting the findings of a survey we conducted with key opinion leaders. The findings highlight the value of a music-based digital therapeutic for treating neuropsychiatric symptoms, particularly agitation and anxiety. We then consider the neural substrates of these neuropsychiatric symptoms before going on to evaluate randomized control trials on the efficacy of music-based interventions in their treatment. Finally, we present our development plans for the adaptation of an existing music-based digital therapeutic that was previously shown to be efficacious in the treatment of adult anxiety symptoms.

Exposure to nonnative-accented speech reduces listening effort and improves social judgments of the speaker.

Prior research has revealed a native-accent advantage, whereby nonnative-accented speech is more difficult to process than native-accented speech. Nonnative-accented speakers also experience more negative social judgments. In the current study, we asked three questions. First, does exposure to nonnative-accented speech increase speech intelligibility or decrease listening effort, thereby narrowing the native-accent advantage? Second, does lower intelligibility or higher listening effort contribute to listeners' negative social judgments of speakers? Third and finally, does increased intelligibility or decreased listening effort with exposure to speech bring about more positive social judgments of speakers? To address these questions, normal-hearing adults listened to a block of English sentences with a native accent and a block with nonnative accent. We found that once participants were accustomed to the task, intelligibility was greater for nonnative-accented speech and increased similarly with exposure for both accents. However, listening effort decreased only for nonnative-accented speech, soon reaching the level of native-accented speech. In addition, lower intelligibility and higher listening effort was associated with lower ratings of speaker warmth, speaker competence, and willingness to interact with the speaker. Finally, competence ratings increased over time to a similar extent for both accents, with this relationship fully mediated by intelligibility and listening effort. These results offer insight into how listeners process and judge unfamiliar speakers.

Community Choir Improves Vocal Production Measures in Individuals Living with Parkinson's Disease.

OBJECTIVES: Parkinson's disease (PD) is a neurodegenerative disease leading to motor impairments and dystonia across diverse muscle groups including vocal muscles. The vocal production challenges associated with PD have received considerably less research attention than the primary gross motor symptoms of the disease despite having a substantial effect on quality of life. Increasingly, people living with PD are discovering group singing as an asset-based approach to community building that is purported to strengthen vocal muscles and improve vocal quality. STUDY DESIGN/METHODS: The present study investigated the impact of community choir on vocal production in people living with PD across two sites. Prior to and immediately following a 12-week community choir at each site, vocal testing included a range of vocal-acoustic measures, including lowest and highest achievable pitch, duration of phonation, loudness, jitter, and shimmer. RESULTS: Results showed that group singing significantly improved some, though not all, measures of vocal production. Group singing improved lowest pitch (both groups), duration (both groups), intensity (one group), and jitter (one group) and shimmer (both groups). CONCLUSIONS: These findings support community choir as a feasible and scalable complementary approach to managing vocal production challenges associated with PD.

Absolute pitch: neurophysiological evidence for early brain activity in prefrontal cortex.

Absolute pitch (AP) is the ability to rapidly label pitch without an external reference. The speed of AP labeling may be related to faster sensory processing. We compared time needed for auditory processing in AP musicians, non-AP musicians, and nonmusicians (NM) using high-density electroencephalographic recording. Participants responded to pure tones and sung voice. Stimuli evoked a negative deflection peaking at ~100 ms (N1) post-stimulus onset, followed by a positive deflection peaking at ~200 ms (P2). N1 latency was shortest in AP, intermediate in non-AP musicians, and longest in NM. Source analyses showed decreased auditory cortex and increased frontal cortex contributions to N1 for complex tones compared with pure tones. Compared with NM, AP musicians had weaker source currents in left auditory cortex but stronger currents in left inferior frontal gyrus (IFG) during N1, and stronger currents in left IFG during P2. Compared with non-AP musicians, AP musicians exhibited stronger source currents in right insula and left IFG during N1, and stronger currents in left IFG during P2. Non-AP musicians had stronger N1 currents in right auditory cortex than nonmusicians. Currents in left IFG and left auditory cortex were correlated to response times exclusively in AP. Findings suggest a left frontotemporal network supports rapid pitch labeling in AP.

A Scoping Review and Field Guide of Theoretical Approaches and Recommendations to Studying the Decision to Adopt Hearing Aids.

OBJECTIVES: Given the low rates of hearing aid adoption among individuals with hearing loss, it is imperative to better understand the decision-making processes leading to greater hearing aid uptake. A careful analysis of the existing literature on theoretical approaches to studying these processes is needed to help researchers frame hypotheses and methodology in studies on audiology. Therefore, we conducted a scoping review with two aims. First, we examine theories that have been used to study research on hearing aid adoption. Second, we propose additional theories from the behavioral sciences that have not yet been used to examine hearing aid uptake but that can inform future research. DESIGN: We identified peer-reviewed publications whose research was driven by one or more theoretical approaches by searching through PubMed, ProQuest PsycINFO, CINHAL Plus, Web of Science, Scopus, and OVID Medline/Embase/PsycINFO. The publications were examined by two researchers for eligibility. RESULTS: Twenty-three papers were included in the analysis. The most common theoretical approaches studied include the Health Belief Model, the Transtheoretical Model of Behavior Change, Self-Determination Theory, and the COM-B Model. Seven other theoretical frameworks based on cognitive psychology and behavioral economics have also appeared in the literature. In addition, we propose considering nudge theory, framing effect, prospect theory, social learning theory, social identity theory, dual process theories, and affective-based theories of decision making when studying hearing aid adoption. CONCLUSIONS: We conclude that, although a number of theories have been considered in research on hearing aid uptake, there are considerable methodological limitations to their use. Furthermore, the field can benefit greatly from the inclusion of novel theoretical approaches drawn from outside of audiology.

Music-based interventions in community settings: Navigating the tension between rigor and ecological validity.

Empirical research of community-based music interventions has advanced to investigate the individual, social, and educational implications of arts-for-wellbeing practices. Here, we present the motivations, aims, hypotheses, and implications of this complex field of inquiry. We describe examples of recent large-scale investigations to reflect on the major methodological challenges. Community-based music interventions strike a balance between the empirical rigor of clinical trials and the demands of ecological validity. We argue that this balance should be viewed as an asset rather than a mere pragmatic compromise. We also offer some perspectives on best-practice models for effectively engaging in this type of work.

The forgotten role of absorption in music reward.

Interindividual differences in music-related reward have been characterized as involving five main facets: musical seeking, emotion evocation, mood regulation, social reward, and sensory-motor. An interesting concept related to how humans decode music as a rewarding experience is music transcendence or absorption (i.e., music-driven states of complete immersion, including momentary loss of self-consciousness or even time-space disorientation). Here, we investigated the relation between previously characterized facets of music reward and individual differences in music absorption. A first sample of participants (N = 370) completed both the Barcelona Music Reward Questionnaire (BMRQ) and the Absorption in Music Scale (AIMS). Results showed that both constructs were highly interrelated (r = 0.78, p < 0.001), indicating that higher music reward sensitivity is associated with a greater tendency to music-related absorption states. In addition, four items from the AIMS were identified as suitable to be added to an extended version of the BMRQ (eBMRQ). A second sample (N = 550) completed the eBMRQ for a validation study. Exploratory and confirmatory factor analyses on the whole sample (N = 920) showed the reliable psychometric properties of the eBMRQ and suggested that taking into account an absorption facet could contribute to a better characterization of individual differences in the sensitivity to experience music-related reward and pleasure.

Efficient nitrogen removal from onsite wastewater by a novel continuous flow biofilter.

Soil-based passive biofiltration system is an economically feasible technology for nitrogen removal from onsite wastewater. However, the conventional design requires a large system footprint with limited treatment capacity. In this study, a novel continuous flow biofilter (CFB) with adjustable recirculation and continuous flow pattern was developed for onsite wastewater treatment with a small footprint. Efficient total nitrogen removal (80.1-97.5%) was observed at various hydraulic loadings (0.03-0.12 m3 m-2 d-1), nitrogen loadings (1.1-8.6 g N m-2 d-1) and recycle ratios (2-3) when treating septic tank effluent (STE), with low effluent TN (0.7-13.6 mg N L-1). Nitrous oxide was observed in the denitrification effluent indicating incomplete denitrification at elevated dissolved oxygen levels (3.3-5.8 mg L-1). Nitrogen removal rate (2.9-7.0 g N m-2 d-1) and ammonium removal rate (2.4-7.2 g N m-2 d-1) were positively correlated with nitrogen loadings increase (1.1-8.6 g N m-2 d-1) but were not significantly impacted by the hydraulic loading rate change (0.08-0.12 m3 m-2 d-1). The total biomass abundance and nitrifying microorganisms decreased significantly as the nitrification columns depth increased, while homogeneous microbial distribution was observed in the denitrification columns. The abundance of ammonium oxidizing archaea (AOA) increased significantly at increased hydraulic and nitrogen loading rate, while the ammonium oxidizing bacteria (AOB) abundance remained steady. The abundance of functional genes involved in denitrification process (nirS, nirK and nosZ) responded differently when hydraulic and nitrogen loading rate changes. Collectively, this study suggested the CFB could efficiently remove nitrogen from onsite wastewater with fluctuating influent compositions and various hydraulic loadings.

The effects of music & auditory beat stimulation on anxiety: A randomized clinical trial.

BACKGROUND AND OBJECTIVES: Music and auditory beat stimulation (ABS) in the theta frequency range (4-7 Hz) are sound-based anxiety treatments that have been independently investigated in prior studies. Here, the anxiety-reducing potential of calm music combined with theta ABS was examined in a large sample of participants. METHODS: An open-label randomized controlled trial was conducted with participants taking anxiolytics (n = 163). Participants were randomly assigned using the Qualtrics randomizer algorithm, to a single session of sound-based treatment in one of four parallel arms: combined (music & ABS; n = 39), music-alone (n = 36), ABS-alone (n = 41), or pink noise (control; n = 47). Pre- and post-intervention somatic and cognitive state anxiety measures were collected along with trait anxiety, personality measures and musical preferences. The study was completed online using a custom application. RESULTS: Based on trait anxiety scores participants were separated into moderate and high trait anxiety sub-groups. Among participants with moderate trait anxiety, we observed reductions in somatic anxiety that were greater in combined and music-alone conditions than in the pink noise condition; and reductions in cognitive state anxiety that were greater in the combined condition than in the music-alone, ABS-alone, and pink noise conditions. While we also observed reductions in somatic and cognitive state anxiety in participants with high trait anxiety, the conditions were not well differentiated. CONCLUSIONS: Sound-based treatments are effective in reducing somatic and cognitive state anxiety. For participants with moderate trait anxiety, combined conditions were most efficacious.

Reduced Semantic Context and Signal-to-Noise Ratio Increase Listening Effort As Measured Using Functional Near-Infrared Spectroscopy.

OBJECTIVES: Understanding speech-in-noise can be highly effortful. Decreasing the signal-to-noise ratio (SNR) of speech increases listening effort, but it is relatively unclear if decreasing the level of semantic context does as well. The current study used functional near-infrared spectroscopy to evaluate two primary hypotheses: (1) listening effort (operationalized as oxygenation of the left lateral PFC) increases as the SNR decreases and (2) listening effort increases as context decreases. DESIGN: Twenty-eight younger adults with normal hearing completed the Revised Speech Perception in Noise Test, in which they listened to sentences and reported the final word. These sentences either had an easy SNR (+4 dB) or a hard SNR (-2 dB), and were either low in semantic context (e.g., "Tom could have thought about the sport") or high in context (e.g., "She had to vacuum the rug"). PFC oxygenation was measured throughout using functional near-infrared spectroscopy. RESULTS: Accuracy on the Revised Speech Perception in Noise Test was worse when the SNR was hard than when it was easy, and worse for sentences low in semantic context than high in context. Similarly, oxygenation across the entire PFC (including the left lateral PFC) was greater when the SNR was hard, and left lateral PFC oxygenation was greater when context was low. CONCLUSIONS: These results suggest that activation of the left lateral PFC (interpreted here as reflecting listening effort) increases to compensate for acoustic and linguistic challenges. This may reflect the increased engagement of domain-general and domain-specific processes subserved by the dorsolateral prefrontal cortex (e.g., cognitive control) and inferior frontal gyrus (e.g., predicting the sensory consequences of articulatory gestures), respectively.

Human mirror neuron system responsivity to unimodal and multimodal presentations of action.

This study aims to clarify unresolved questions from two earlier studies by McGarry et al. Exp Brain Res 218(4): 527-538, 2012 and Kaplan and Iacoboni Cogn Process 8: 103-113, 2007 on human mirror neuron system (hMNS) responsivity to multimodal presentations of actions. These questions are: (1) whether the two frontal areas originally identified by Kaplan and Iacoboni (ventral premotor cortex [vPMC] and inferior frontal gyrus [IFG]) are both part of the hMNS (i.e., do they respond to execution as well as observation), (2) whether both areas yield effects of biologicalness (biological, control) and modality (audio, visual, audiovisual), and (3) whether the vPMC is preferentially responsive to multimodal input. To resolve these questions about the hMNS, we replicated and extended McGarry et al.'s electroencephalography (EEG) study, while incorporating advanced source localization methods. Participants were asked to execute movements (ripping paper) as well as observe those movements across the same three modalities (audio, visual, and audiovisual), all while 64-channel EEG data was recorded. Two frontal sources consistent with those identified in prior studies showed mu event-related desynchronization (mu-ERD) under execution and observation conditions. These sources also showed a greater response to biological movement than to control stimuli as well as a distinct visual advantage, with greater responsivity to visual and audiovisual compared to audio conditions. Exploratory analyses of mu-ERD in the vPMC under visual and audiovisual observation conditions suggests that the hMNS tracks the magnitude of visual movement over time.

Audio and visual speech emotion activate the left pre-supplementary motor area.

Sensorimotor brain areas have been implicated in the recognition of emotion expressed on the face and through nonverbal vocalizations. However, no previous study has assessed whether sensorimotor cortices are recruited during the perception of emotion in speech-a signal that includes both audio (speech sounds) and visual (facial speech movements) components. To address this gap in the literature, we recruited 24 participants to listen to speech clips produced in a way that was either happy, sad, or neutral in expression. These stimuli also were presented in one of three modalities: audio-only (hearing the voice but not seeing the face), video-only (seeing the face but not hearing the voice), or audiovisual. Brain activity was recorded using electroencephalography, subjected to independent component analysis, and source-localized. We found that the left presupplementary motor area was more active in response to happy and sad stimuli than neutral stimuli, as indexed by greater mu event-related desynchronization. This effect did not differ by the sensory modality of the stimuli. Activity levels in other sensorimotor brain areas did not differ by emotion, although they were greatest in response to visual-only and audiovisual stimuli. One possible explanation for the pre-SMA result is that this brain area may actively support speech emotion recognition by using our extensive experience expressing emotion to generate sensory predictions that in turn guide our perception.

A Comparison between a remote testing and a laboratory test setting for evaluating emotional responses to non-speech sounds.

OBJECTIVE: To evaluate remote testing as a tool for measuring emotional responses to non-speech sounds. DESIGN: Participants self-reported their hearing status and rated valence and arousal in response to non-speech sounds on an Internet crowdsourcing platform. These ratings were compared to data obtained in a laboratory setting with participants who had confirmed normal or impaired hearing. STUDY SAMPLE: Adults with normal and impaired hearing. RESULTS: In both settings, participants with hearing loss rated pleasant sounds as less pleasant than did their peers with normal hearing. The difference in valence ratings between groups was generally smaller when measured in the remote setting than in the laboratory setting. This difference was the result of participants with normal hearing rating sounds as less extreme (less pleasant, less unpleasant) in the remote setting than did their peers in the laboratory setting, whereas no such difference was noted for participants with hearing loss. Ratings of arousal were similar from participants with normal and impaired hearing; the similarity persisted in both settings. CONCLUSIONS: In both test settings, participants with hearing loss rated pleasant sounds as less pleasant than did their normal hearing counterparts. Future work is warranted to explain the ratings of participants with normal hearing.

Neural Dynamics of Inhibitory Control in Musicians with Absolute Pitch: Theta Synchrony as an Oscillatory Signature of Information Conflict.

Absolute pitch (AP) is the ability to identify an auditory pitch without prior context. Current theories posit AP involves automatic retrieval of referents. We tested interference in well-matched AP musicians, non-AP musicians, and nonmusicians with three auditory Stroop tasks. Stimuli were one of two sung pitches with congruent or incongruent verbal cues. The tasks used different lexicons: binary concrete adjectives (i.e., words: Low/High), syllables with no obvious semantic properties (i.e., solmization: Do/So), and abstract semiotic labels (i.e., orthographic: C/G). Participants were instructed to respond to pitch regardless of verbal information during electroencephalographic recording. Incongruent stimuli of words and solmization tasks increased errors and slowed response times (RTs), which was reversed in nonmusicians for the orthographic task. AP musicians made virtually no errors, but their RTs slowed for incongruent stimuli. Frontal theta (4-7 Hz) event-related synchrony was significantly enhanced during incongruence between 350 and 550 ms poststimulus onset in AP, regardless of lexicon or behavior. This effect was found in non-AP musicians and nonmusicians for word task, while orthographic task showed a reverse theta congruency effect. Findings suggest theta synchrony indexes conflict detection in AP. High beta (21-29 Hz) desynchrony indexes response conflict detection in non-AP musicians. Alpha (8-12 Hz) synchrony may reflect top-down attention.

Field Attenuation of Foam Earplugs.

BACKGROUND: Hearing protection devices (HPDs) are often used in the workplace to prevent hearing damage caused by noise. However, a factor that can lead to hearing loss in the workplace is improper HPD fitting, and the previous literature has shown that instructing workers on how to properly insert their HPDs can make a significant difference in the degree of attenuation. METHODS: Two studies were completed on a total of 33 Hydro One workers. A FitCheck Solo field attenuation estimation system was used to measure the personal attenuation rating (PAR) before and after providing one-on-one fitting instructions. In addition, external ear canal diameters were measured, and a questionnaire with items related to frequency of use, confidence, and discomfort was administered. RESULTS: Training led to an improvement in HPD attenuation, particularly for participants with poorer PARs before training. The questionnaire results indicated that much HPD discomfort is caused by heat, humidity, and communication difficulties. External ear canal asymmetry did not appear to significantly influence the measured PAR. CONCLUSION: In accordance with the previous literature, our studies suggest that one-on-one instruction is an effective training method for HPD use. Addressing discomfort issues from heat, humidity, and communication issues could help to improve the use of HPDs in the workplace. Further research into the effects of canal asymmetry on the PAR is needed.

Comparing verbal working memory load in auditory and visual modalities using functional near-infrared spectroscopy.

The verbal identity n-back task is commonly used to assess verbal working memory (VWM) capacity. Only three studies have compared brain activation during the n-back when using auditory and visual stimuli. The earliest study, a positron emission tomography study of the 3-back, found no differences in VWM-related brain activation between n-back modalities. In contrast, two subsequent functional magnetic resonance imaging (fMRI) studies of the 2-back found that auditory VWM was associated with greater left dorsolateral prefrontal cortex (DL-PFC) activation than visual VWM, perhaps suggesting that auditory VWM requires more cognitive effort than its visual counterpart. The current study aimed to assess whether DL-PFC activation (i.e., cognitive effort) differs by VWM modality. To do this, 16 younger adults completed an auditory and visual n-back, both at four levels of VWM load. Concurrently, activation of the PFC was measured using functional near-infrared spectroscopy (fNIRS), a silent neuroimaging method. We found that DL-PFC activation increased with VWM load, but it was not affected by VWM modality or the interaction between load and modality. This supports the view that both VWM modalities require similar cognitive effort, and perhaps that previous fMRI results were an artefact of scanner noise. We also found that, across conditions, DL-PFC activation was positively correlated with reaction time. This may further support DL-PFC activation as an index of cognitive effort, and fNIRS as a method to measure it.

Neural and Behavioral Evidence for Vibrotactile Beat Perception and Bimodal Enhancement.

The ability to synchronize movements to a rhythmic stimulus, referred to as sensorimotor synchronization (SMS), is a behavioral measure of beat perception. Although SMS is generally superior when rhythms are presented in the auditory modality, recent research has demonstrated near-equivalent SMS for vibrotactile presentations of isochronous rhythms [Ammirante, P., Patel, A. D., & Russo, F. A. Synchronizing to auditory and tactile metronomes: A test of the auditory-motor enhancement hypothesis. Psychonomic Bulletin & Review, 23, 1882-1890, 2016]. The current study aimed to replicate and extend this study by incorporating a neural measure of beat perception. Nonmusicians were asked to tap to rhythms or to listen passively while EEG data were collected. Rhythmic complexity (isochronous, nonisochronous) and presentation modality (auditory, vibrotactile, bimodal) were fully crossed. Tapping data were consistent with those observed by Ammirante et al. (2016), revealing near-equivalent SMS for isochronous rhythms across modality conditions and a drop-off in SMS for nonisochronous rhythms, especially in the vibrotactile condition. EEG data revealed a greater degree of neural entrainment for isochronous compared to nonisochronous trials as well as for auditory and bimodal compared to vibrotactile trials. These findings led us to three main conclusions. First, isochronous rhythms lead to higher levels of beat perception than nonisochronous rhythms across modalities. Second, beat perception is generally enhanced for auditory presentations of rhythm but still possible under vibrotactile presentation conditions. Finally, exploratory analysis of neural entrainment at harmonic frequencies suggests that beat perception may be enhanced for bimodal presentations of rhythm.

Indigenous youth reconnect with cultural identity: The evaluation of a community- and school-based traditional music program.

Reconnecting Indigenous youth with their cultural traditions has been identified as an essential part of healing the intergenerational effects of forced assimilation policies. Past work suggests that learning the music of one's culture can foster cultural identity and community bonding, which may serve as protective factors for well-being. An 8-week traditional song and dance program was implemented in a school setting for Indigenous youth. An evaluation was conducted using a mixed-method design to determine the impact of the program on 35 youth in the community. A triangulation of qualitative and quantitative data revealed several important themes, including personal development, cultural development, social development, student engagement in school-based programming, and perpetuating cultural knowledge. The program provided students with an opportunity to connect with their cultural traditions through activities that encouraged self and cultural expression. Community responses suggested that this type of programming is highly valued among Indigenous communities.

Achieving business resiliency to natural disasters through the lens of risk management and insurance.

Natural disasters have been occurring more frequently and with greater potency, creating a real and heightened financial and operational risk to businesses around the globe. This paper aims to enhance traditional business continuity techniques and strategies by discussing how risk management, insurance and claims knowledge can form a robust platform from which to minimise the impacts of natural disasters on business. To this end, the paper combines professional knowledge from the fields of risk management, disaster response and insurance claims recovery to offer best practices in the key phases of planning and response.