Biological impact of preschool music classes on processing speech in noise

Different Weighting of Auditory Memory and Attention as Cognitive Resources in Bilingual's Speech Perception in Noise

Understanding speech in noisy environments is a challenging task that requires sensory and cognitive functions, including memory and auditory attention. Bilinguals and monolinguals have different scores of these abilities. This study aims to investigate the relationship between these cognitive skills and compare Turkish-Persian bilinguals with Persian monolinguals regarding speech-in-noise scores. 45 Turkish-Persian bilinguals and 45 Persian monolinguals, aged 18-25 (mean age 21.67), with normal hearing, participated in a speech in noise, auditory working memory, and auditory attention tests. The bilingual group performed significantly worse than the monolingual group in the quick speech-in-noise and n-back auditory working memory tests (p < 0.05). However, their score on the auditory attention test was better (p < 0.05). Bilinguals showed a significant correlation between auditory working memory, auditory attention, and speech perception in noise. A linear regression validated the proposed model, predicting speech perception scores in noise based on auditory attention and auditory working memory in bilinguals (r2: 0.20, P: 0.008). Research suggests that various cognitive factors impact an individual's ability to perceive speech in noisy environments. Specifically, auditory attention and working memory have different levels of influence on this skill for bilingual individuals.

Cognitive enrichment through art: a randomized controlled trial on the effect of music or visual arts group practice on cognitive and brain development of young children

BACKGROUND

The optimal stimulation for brain development in the early academic years remains unclear. Current research suggests that musical training has a more profound impact on children's executive functions (EF) compared to other art forms. What is crucially lacking is a large-scale, long-term genuine randomized controlled trial (RCT) in cognitive neuroscience, comparing musical instrumental training (MIP) to another art form, and a control group (CG). This study aims to fill this gap by using machine learning to develop a multivariate model that tracks the interconnected brain and EF development during the academic years, with or without music or other art training.

METHODS

The study plans to enroll 150 children aged 6-8 years and randomly assign them to three groups: Orchestra in Class (OC), Visual Arts (VA), and a control group (CG). Anticipating a 30% attrition rate, each group aims to retain at least 35 participants. The research consists of three analytical stages: 1) baseline analysis correlating EF, brain data, age, gender, and socioeconomic status, 2) comparison between groups and over time of EF brain and behavioral development and their interactions, including hypothesis testing, and 3) exploratory analysis combining behavioral and brain data. The intervention includes intensive art classes once a week, and incremental home training over two years, with the CG receiving six annual cultural outings.

DISCUSSION

This study examines the potential benefits of intensive group arts education, especially contrasting music with visual arts, on EF development in children. It will investigate how artistic enrichment potentially influences the presumed typical transition from a more unified to a more multifaceted EF structure around age eight, comparing these findings against a minimally enriched active control group. This research could significantly influence the incorporation of intensive art interventions in standard curricula.

TRIAL REGISTRATION

The project was accepted after peer-review by the Swiss National Science Foundation (SNSF no. 100014_214977) on March 29, 2023. The study protocol received approval from the Cantonal Commission for Ethics in Human Research of Geneva (CCER, BASEC-ID 2023-01016), which is part of Swiss ethics, on October 25, 2023. The study is registered at clinicaltrials.gov (NCT05912270).

Construction of a Chinese traditional instrumental music dataset: A validated set of naturalistic affective music excerpts

Music is omnipresent among human cultures and moves us both physically and emotionally. The perception of emotions in music is influenced by both psychophysical and cultural factors. Chinese traditional instrumental music differs significantly from Western music in cultural origin and music elements. However, previous studies on music emotion perception are based almost exclusively on Western music. Therefore, the construction of a dataset of Chinese traditional instrumental music is important for exploring the perception of music emotions in the context of Chinese culture. The present dataset included 273 10-second naturalistic music excerpts. We provided rating data for each excerpt on ten variables: familiarity, dimensional emotions (valence and arousal), and discrete emotions (anger, gentleness, happiness, peacefulness, sadness, solemnness, and transcendence). The excerpts were rated by a total of 168 participants on a seven-point Likert scale for the ten variables. Three labels for the excerpts were obtained: familiarity, discrete emotion, and cluster. Our dataset demonstrates good reliability, and we believe it could contribute to cross-cultural studies on emotional responses to music.

Music as a window into real-world communication

Communication has been studied extensively in the context of speech and language. While speech is tremendously effective at transferring ideas between people, music is another communicative mode that has a unique power to bring people together and transmit a rich tapestry of emotions, through joint music-making and listening in a variety of everyday contexts. Research has begun to examine the behavioral and neural correlates of the joint action required for successful musical interactions, but it has yet to fully account for the rich, dynamic, multimodal nature of musical communication. We review the current literature in this area and propose that naturalistic musical paradigms will open up new ways to study communication more broadly.

The Effects of Monaural Stimulation on Frequency-Following Responses in Adults Who Can Sing in Tune and Those Who Cannot

Introduction  Musicians have an advantage over non-musicians in detecting, perceiving, and processing nonverbal (i.e., environmental sounds, tones and others) and verbal sounds (i.e., consonant, vowel, phrases and others) as well as instrumental sounds. In contrast to the high skill of musicians, there is another group of people who are tone-deaf and have difficulty in distinguishing musical sounds or singing in tune. These sounds can originate in different ways, such as a musical instrument, orchestra, or the human voice. Objective  The objective of the present work is to study frequency-following responses (FFRs) in individuals who can sing in-tune and those who sing off-tune. Methods  Electrophysiological responses were recorded in 37 individuals divided in two groups: (i) control group (CG) with professional musicians, and (ii) experimental group (EG) with non-musicians. Results  There was homogeneity between the two groups regarding age and gender. The CG had more homogeneous responses in the latency of the FFRs waves when responses between the right and left ears were compared to those of the EG. Conclusion  This study showed that monaural stimulation (right or left) in an FFR test is useful for demonstrating impairment of speech perception in individuals who sing off tune. The response of the left ear appears to present more subtlety and reliability when identifying the coding of speech sound in individuals who sing off tune.

Training Programs for Improving Speech Perception in Noise: A Review

Understanding speech in the presence of noise is difficult and challenging, even for people with normal hearing. Accurate pitch perception, coding and decoding of temporal and intensity cues, and cognitive factors are involved in speech perception in noise (SPIN); disruption in any of these can be a barrier to SPIN. Because the physiological representations of sounds can be corrected by exercises, training methods for any impairment can be used to improve speech perception. This study describes the various types of bottom-up training methods: pitch training based on fundamental frequency (F0) and harmonics; spatial, temporal, and phoneme training; and top-down training methods, such as cognitive training of functional memory. This study also discusses music training that affects both bottom-up and top-down components and speech training in noise. Given the effectiveness of all these training methods, we recommend identifying the defects underlying SPIN disorders and selecting the best training approach.

A Home-Based Approach to Auditory Brainstem Response Measurement: Proof-of-Concept and Practical Guidelines

Broad-scale neuroscientific investigations of diverse human populations are difficult to implement. This is because the primary neuroimaging methods (magnetic resonance imaging, electroencephalography [EEG]) historically have not been portable, and participants may be unable or unwilling to travel to test sites. Miniaturization of EEG technologies has now opened the door to neuroscientific fieldwork, allowing for easier access to under-represented populations. Recent efforts to conduct auditory neuroscience outside a laboratory setting are reviewed and then an in-home technique for recording auditory brainstem responses (ABRs) and frequency-following responses (FFRs) in a home setting is introduced. As a proof of concept, we have conducted two in-home electrophysiological studies: one in 27 children aged 6 to 16 years (13 with autism spectrum disorder) and another in 12 young adults aged 18 to 27 years, using portable electrophysiological equipment to record ABRs and FFRs to click and speech stimuli, spanning rural and urban and multiple homes and testers. We validate our fieldwork approach by presenting waveforms and data on latencies and signal-to-noise ratio. Our findings demonstrate the feasibility and utility of home-based ABR/FFR techniques, paving the course for larger fieldwork investigations of populations that are difficult to test or recruit. We conclude this tutorial with practical tips and guidelines for recording ABRs and FFRs in the field and discuss possible clinical and research applications of this approach.

Bilinguals' speech perception in noise: Perceptual and neural associations

The current study characterized subcortical speech sound processing among monolinguals and bilinguals in quiet and challenging listening conditions and examined the relation between subcortical neural processing and perceptual performance. A total of 59 normal-hearing adults, ages 19–35 years, participated in the study: 29 native Hebrew-speaking monolinguals and 30 Arabic-Hebrew-speaking bilinguals. Auditory brainstem responses to speech sounds were collected in a quiet condition and with background noise. The perception of words and sentences in quiet and background noise conditions was also examined to assess perceptual performance and to evaluate the perceptual-physiological relationship. Perceptual performance was tested among bilinguals in both languages (first language (L1-Arabic) and second language (L2-Hebrew)). The outcomes were similar between monolingual and bilingual groups in quiet. Noise, as expected, resulted in deterioration in perceptual and neural responses, which was reflected in lower accuracy in perceptual tasks compared to quiet, and in more prolonged latencies and diminished neural responses. However, a mixed picture was observed among bilinguals in perceptual and physiological outcomes in noise. In the perceptual measures, bilinguals were significantly less accurate than their monolingual counterparts. However, in neural responses, bilinguals demonstrated earlier peak latencies compared to monolinguals. Our results also showed that perceptual performance in noise was related to subcortical resilience to the disruption caused by background noise. Specifically, in noise, increased brainstem resistance (i.e., fewer changes in the fundamental frequency (F0) representations or fewer shifts in the neural timing) was related to better speech perception among bilinguals. Better perception in L1 in noise was correlated with fewer changes in F0 representations, and more accurate perception in L2 was related to minor shifts in auditory neural timing. This study delves into the importance of using neural brainstem responses to speech sounds to differentiate individuals with different language histories and to explain inter-subject variability in bilinguals’ perceptual abilities in daily life situations.

Acoustics versus linguistics? Context is Part and Parcel to lateralized processing of the parts and parcels of speech

The purpose of this review is to provide an accessible exploration of key considerations of lateralization in speech and non-speech perception using clear and defined language. From these considerations, the primary arguments for each side of the linguistics versus acoustics debate are outlined and explored in context of emerging integrative theories. This theoretical approach entails a perspective that linguistic and acoustic features differentially contribute to leftward bias, depending on the given context. Such contextual factors include stimulus parameters and variables of stimulus presentation (e.g., noise/silence and monaural/binaural) and variances in individuals (sex, handedness, age, and behavioural ability). Discussion of these factors and their interaction is also aimed towards providing an outline of variables that require consideration when developing and reviewing methodology of acoustic and linguistic processing laterality studies. Thus, there are three primary aims in the present paper: (1) to provide the reader with key theoretical perspectives from the acoustics/linguistics debate and a synthesis of the two viewpoints, (2) to highlight key caveats for generalizing findings regarding predominant models of speech laterality, and (3) to provide a practical guide for methodological control using predominant behavioural measures (i.e., gap detection and dichotic listening tasks) and/or neurophysiological measures (i.e., mismatch negativity) of speech laterality.

Evaluation of Auditory Stream Segregation in Musicians and Nonmusicians

Introduction  One of the major cues that help in auditory stream segregation is spectral profiling. Musicians are trained to perceive a fine structural variation in the acoustic stimuli and have enhanced temporal perception and speech perception in noise.

Objective  To analyze the differences in spectral profile thresholds in musicians and nonmusicians.

Methods  The spectral profile analysis threshold was compared between 2 groups (musicians and nonmusicians) in the age range between 15 and 30 years old. The stimuli had 5 harmonics, all at the same amplitude (f0 = 330 Hz, mi4). The third (variable tone) has a similar harmonic structure; however, the amplitude of the third harmonic component was higher, producing a different timbre in comparison with the standards. The subject had to identify the odd timbre tone. The testing was performed at 60 dB HL in a sound-treated room.

Results  The results of the study showed that the profile analysis thresholds were significantly better in musicians compared with nonmusicians. The result of the study also showed that the profile analysis thresholds were better with an increase in the duration of music training. Thus, improved auditory processing in musicians could have resulted in a better profile analysis threshold.

Conclusions  Auditory stream segregation was found to be better in musicians compared with nonmusicians, and the performance improved with an increase in several years of training. However, further studies are essential on a larger group with more variables for validation of the results.

Speech-evoked auditory brainstem response; electrophysiological evidence of upper brainstem facilitative role on sound lateralization in noise

BACKGROUND AND AIM

Sound lateralization/localization is one of the most important auditory processing abilities, which plays approved role in auditory streaming and speech perception in challenging situations like noisy places. In addition to the main role of lower brainstem centers like superior olivary complex in sound lateralization, efferent auditory system effects on improving auditory skills in everyday auditory challenging positions were revealed. This study evaluated noise effects on lateralization scores in correlation with an objective electrophysiologic test (Speech-ABR in noise), which objectively shows cumulative effects of the afferent and efferent auditory systems at the inferior colliculus and upper brainstem pathway.

METHOD

Fourteen normal-hearing subjects in the age range of 18 to 25 participated in this study. Lateralization scores in the quiet and noisy modes were evaluated. Speech-ABR in both ears for quiet mode and three different contralateral noise levels (SNR = + 5, 0, - 5) were recorded, too. Correlation of lateralization scores and Speech-ABR changes in noise was studied.

RESULTS

Significant decrease of lateralization scores with latency increase and amplitude decrease of Speech-ABR transient peaks (V, A, O) was seen with noise presentation. A high positive correlation between lateralization decrease with latency increase of onset peaks (V, A) and amplitude decrease of transient peaks (V, A, O) was found in low signal-to-noise ratios.

CONCLUSION

The study revealed that in high challenging auditory situations like auditory lateralization in noise, upper brainstem centers and pathways play a facilitative role for main auditory lateralization centers in lower levels.

DEVELOPMENT AND VALIDATION OF A METHOD TO ENHANCE AUDITORY ATTENTION DURING CONTINUOUS SPEECH-SHAPED NOISE ENVIRONMENT

Auditory training (AT) may strengthen auditory skills that help human not only in on-task auditory perception performance but in continuous speech-shaped noise (SSN) environment. AT based on musical material has provided some evidence for an “auditory advantage” in understanding speech-in-noise (SIN), but with a long period training and complex procedure. Experimental research is essential to develop a simplified method named auditory target tracking training (ATT) which refined from musical material is necessary to determine the benefits of training. We developed two kinds of refined AT method: basic auditory target tracking (BAT) training and enhanced auditory target tracking (EAT) training to adult participants ([Formula: see text]) separately for 20 units, assessing performance to perceive speech in noise environment after training. The EAT group presented better speech perception performance than the other groups and no significant differences between BAT group and control group. The training effect of EAT is the most significant when uni-gender SSN and [Formula: see text] dB. Outcomes suggest that efficacy of trained EAT can improve speech perception performance and selective attention during SSN environment. These findings provide an important link between musical-based training and auditory selective attention in real-world, and extended to special vocational training.

Treinamento musical e habilidades do processamento auditivo em crianças: revisão sistemática

RESUMO Objetivo Verificar a contribuição do treinamento musical nas habilidades do processamento auditivo em crianças. Estratégia de pesquisa Realizou-se uma busca no mês de agosto de 2018, usando os descritores Music, Child, Childhood, Children, Evoked Potentials, Auditory, Auditory Perception, Auditory Processing, utilizando o operador AND. Critérios de seleção Como questão norteadora, adotou-se a seguinte pergunta: “o que existe na literatura científica sobre a contribuição do treinamento musical nas habilidades de processamento auditivo em crianças?” Após, foram selecionados somente ensaios clínicos controlados na população infantil, estudos publicados em inglês, português e espanhol. Resultados A estratégia de busca resultou na seleção de dez artigos. Os estudos evidenciaram diversas habilidades testadas e diferentes formas de avaliação. Conclusão Com base nos achados, pode-se concluir que o treinamento musical melhora e aprimora as habilidades de processamento auditivo, de forma que quanto maior o tempo de treinamento, mais essas habilidades são reforçadas. Dessa forma, o treinamento musical mostra-se um método eficaz e com potencialidade para ser utilizado em crianças, tanto no período de desenvolvimento da comunicação oral e escrita, para auxiliar a aquisição das habilidades auditivas, como após a aquisição afim de aprimorá-las.

Behavioral and electrophysiological investigation of speech perception deficits in silence, noise and envelope conditions in developmental dyslexia

The present study investigated whether children with developmental dyslexia showed specific deficits in the perception of three phonetic features (voicing, place, and manner of articulation) in optimal (silence) and degraded listening conditions (envelope-coded speech versus noise), using both standard behavioral and electrophysiological measures. Performance of children with dyslexia was compared to that of younger typically developing children who were matched in terms of reading age. Results showed no significant group differences in response accuracy except for the reception of place-of-articulation in noise. However, dyslexic children responded more slowly than typically developing children across all conditions with larger deficits in noise than in envelope than in silence. At the neural level, dyslexic children exhibited reduced N1 components in silence and the reduction of N1 amplitude was more pronounced for voicing than for the other phonetic features. In the envelope condition, the N1 was localized over the right hemisphere and it was larger for typically developing readers than for dyslexic children. Finally, in stationary noise, the N1 to place of articulation was clearly delayed in children with dyslexia, which suggests a temporal de-organization in the most adverse listening conditions. The results clearly show abnormal neural processing to speech sounds in all conditions. They are discussed in the context of recent theories on perceptual noise exclusion, neural noise and temporal sampling.

Can very early music interventions promote at-risk infants' development?

Music and musical activities are often a natural part of parenting. As accumulating evidence shows, music can promote auditory and language development in infancy and early childhood. It may even help to support auditory and language skills in infants whose development is compromised by heritable conditions, like the reading deficit dyslexia, or by environmental factors, such as premature birth. For example, infants born to dyslexic parents can have atypical brain responses to speech sounds and subsequent challenges in language development. Children born very preterm, in turn, have an increased likelihood of sensory, cognitive, and motor deficits. To ameliorate these deficits, we have developed early interventions focusing on music. Preliminary results of our ongoing longitudinal studies suggest that music making and parental singing promote infants' early language development and auditory neural processing. Together with previous findings in the field, the present studies highlight the role of active, social music making in supporting auditory and language development in at-risk children and infants. Once completed, the studies will illuminate both risk and protective factors in development and offer a comprehensive model of understanding the promises of music activities in promoting positive developmental outcomes during the first years of life.

Musical training shapes neural responses to melodic and prosodic expectation

Current research on music processing and syntax or semantics in language suggests that music and language share partially overlapping neural resources. Pitch also constitutes a common denominator, forming melody in music and prosody in language. Further, pitch perception is modulated by musical training. The present study investigated how music and language interact on pitch dimension and whether musical training plays a role in this interaction. For this purpose, we used melodies ending on an expected or unexpected note (melodic expectancy being estimated by a computational model) paired with prosodic utterances which were either expected (statements with falling pitch) or relatively unexpected (questions with rising pitch). Participants' (22 musicians, 20 nonmusicians) ERPs and behavioural responses in a statement/question discrimination task were recorded. Participants were faster for simultaneous expectancy violations in the melodic and linguistic stimuli. Further, musicians performed better than nonmusicians, which may be related to their increased pitch tracking ability. At the neural level, prosodic violations elicited a front-central positive ERP around 150 ms after the onset of the last word/note, while musicians presented reduced P600 in response to strong incongruities (questions on low-probability notes). Critically, musicians' P800 amplitudes were proportional to their level of musical training, suggesting that expertise might shape the pitch processing of language. The beneficial aspect of expertise could be attributed to its strengthening effect of general executive functions. These findings offer novel contributions to our understanding of shared higher-order mechanisms between music and language processing on pitch dimension, and further demonstrate a potential modulation by musical expertise.

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Melodic expectancy influences the processing of prosodic expectancy.

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Musical expertise modulates pitch processing in music and language.

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Musicians have a more refined response to pitch.

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Musicians' neural responses are proportional to their level of musical expertise.

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Possible association between the P200 neural component and behavioural facilitation.

Professional Music Training and Novel Word Learning: From Faster Semantic Encoding to Longer-lasting Word Representations

On the basis of previous results showing that music training positively influences different aspects of speech perception and cognition, the aim of this series of experiments was to test the hypothesis that adult professional musicians would learn the meaning of novel words through picture–word associations more efficiently than controls without music training (i.e., fewer errors and faster RTs). We also expected musicians to show faster changes in brain electrical activity than controls, in particular regarding the N400 component that develops with word learning. In line with these hypotheses, musicians outperformed controls in the most difficult semantic task. Moreover, although a frontally distributed N400 component developed in both groups of participants after only a few minutes of novel word learning, in musicians this frontal distribution rapidly shifted to parietal scalp sites, as typically found for the N400 elicited by known words. Finally, musicians showed evidence for better long-term memory for novel words 5 months after the main experimental session. Results are discussed in terms of cascading effects from enhanced perception to memory as well as in terms of multifaceted improvements of cognitive processing due to music training. To our knowledge, this is the first report showing that music training influences semantic aspects of language processing in adults. These results open new perspectives for education in showing that early music training can facilitate later foreign language learning. Moreover, the design used in the present experiment can help to specify the stages of word learning that are impaired in children and adults with word learning difficulties.

Skilled musicians are not subject to the McGurk effect

The McGurk effect is a compelling illusion in which humans auditorily perceive mismatched audiovisual speech as a completely different syllable. In this study evidences are provided that professional musicians are not subject to this illusion, possibly because of their finer auditory or attentional abilities. 80 healthy age-matched graduate students volunteered to the study. 40 were musicians of Brescia Luca Marenzio Conservatory of Music with at least 8–13 years of musical academic studies. /la/, /da/, /ta/, /ga/, /ka/, /na/, /ba/, /pa/ phonemes were presented to participants in audiovisual congruent and incongruent conditions, or in unimodal (only visual or only auditory) conditions while engaged in syllable recognition tasks. Overall musicians showed no significant McGurk effect for any of the phonemes. Controls showed a marked McGurk effect for several phonemes (including alveolar-nasal, velar-occlusive and bilabial ones). The results indicate that the early and intensive musical training might affect the way the auditory cortex process phonetic information.

Neurobiology of Everyday Communication: What Have We Learned From Music?

Sound is an invisible but powerful force that is central to everyday life. Studies in the neurobiology of everyday communication seek to elucidate the neural mechanisms underlying sound processing, their stability, their plasticity, and their links to language abilities and disabilities. This sound processing lies at the nexus of cognitive, sensorimotor, and reward networks. Music provides a powerful experimental model to understand these biological foundations of communication, especially with regard to auditory learning. We review studies of music training that employ a biological approach to reveal the integrity of sound processing in the brain, the bearing these mechanisms have on everyday communication, and how these processes are shaped by experience. Together, these experiments illustrate that music works in synergistic partnerships with language skills and the ability to make sense of speech in complex, everyday listening environments. The active, repeated engagement with sound demanded by music making augments the neural processing of speech, eventually cascading to listening and language. This generalization from music to everyday communications illustrates both that these auditory brain mechanisms have a profound potential for plasticity and that sound processing is biologically intertwined with listening and language skills. A new wave of studies has pushed neuroscience beyond the traditional laboratory by revealing the effects of community music training in underserved populations. These community-based studies reinforce laboratory work highlight how the auditory system achieves a remarkable balance between stability and flexibility in processing speech. Moreover, these community studies have the potential to inform health care, education, and social policy by lending a neurobiological perspective to their efficacy.

The association of noise sensitivity with music listening, training, and aptitude

After intensive, long-term musical training, the auditory system of a musician is specifically tuned to perceive musical sounds. We wished to find out whether a musician's auditory system also develops increased sensitivity to any sound of everyday life, experiencing them as noise. For this purpose, an online survey, including questionnaires on noise sensitivity, musical background, and listening tests for assessing musical aptitude, was administered to 197 participants in Finland and Italy. Subjective noise sensitivity (assessed with the Weinstein's Noise Sensitivity Scale) was analyzed for associations with musicianship, musical aptitude, weekly time spent listening to music, and the importance of music in each person's life (or music importance). Subjects were divided into three groups according to their musical expertise: Nonmusicians (N = 103), amateur musicians (N = 44), and professional musicians (N = 50). The results showed that noise sensitivity did not depend on musical expertise or performance on musicality tests or the amount of active (attentive) listening to music. In contrast, it was associated with daily passive listening to music, so that individuals with higher noise sensitivity spent less time in passive (background) listening to music than those with lower sensitivity to noise. Furthermore, noise-sensitive respondents rated music as less important in their life than did individuals with lower sensitivity to noise. The results demonstrate that the special sensitivity of the auditory system derived from musical training does not lead to increased irritability from unwanted sounds. However, the disposition to tolerate contingent musical backgrounds in everyday life depends on the individual's noise sensitivity.

Music training alters the course of adolescent auditory development

Fundamental changes in brain structure and function during adolescence are well-characterized, but the extent to which experience modulates adolescent neurodevelopment is not. Musical experience provides an ideal case for examining this question because the influence of music training begun early in life is well-known. We investigated the effects of in-school music training, previously shown to enhance auditory skills, versus another in-school training program that did not focus on development of auditory skills (active control). We tested adolescents on neural responses to sound and language skills before they entered high school (pretraining) and again 3 y later. Here, we show that in-school music training begun in high school prolongs the stability of subcortical sound processing and accelerates maturation of cortical auditory responses. Although phonological processing improved in both the music training and active control groups, the enhancement was greater in adolescents who underwent music training. Thus, music training initiated as late as adolescence can enhance neural processing of sound and confer benefits for language skills. These results establish the potential for experience-driven brain plasticity during adolescence and demonstrate that in-school programs can engender these changes.

Emergence of biological markers of musicianship with school-based music instruction

Musician children and adults demonstrate biological distinctions in auditory processing relative to nonmusicians. For example, musician children and adults have more robust neural encoding of speech harmonics, more adaptive sound processing, and more precise neural encoding of acoustically similar sounds; these enhancements may contribute to musicians' linguistic advantages, such as for hearing speech in noise and reading. Such findings have inspired proposals that the auditory and cognitive stimulation induced by musical practice renders musicians enhanced according to biological metrics germane to communication. Cross-sectional methodologies comparing musicians with nonmusicians, however, are limited by the inability to disentangle training-related effects from demographic and innate qualities that may predistinguish musicians. Over the past several years, our laboratory has addressed this problem by examining the emergence of neural markers of musicianship in children and adolescents using longitudinal approaches to track the development of biological indices of speech processing. This work was conducted in partnership with successful community-based music programs, thus avoiding reliance on a synthetic program for the purposes of laboratory study. Outcomes indicate that many of musicians' auditory-related biological enhancements emerge with training and may promote the acquisition of language skills, including in at-risk populations.

Music training and speech perception: a gene-environment interaction

Claims of beneficial side effects of music training are made for many different abilities, including verbal and visuospatial abilities, executive functions, working memory, IQ, and speech perception in particular. Such claims assume that music training causes the associations even though children who take music lessons are likely to differ from other children in music aptitude, which is associated with many aspects of speech perception. Music training in childhood is also associated with cognitive, personality, and demographic variables, and it is well established that IQ and personality are determined largely by genetics. Recent evidence also indicates that the role of genetics in music aptitude and music achievement is much larger than previously thought. In short, music training is an ideal model for the study of gene-environment interactions but far less appropriate as a model for the study of plasticity. Children seek out environments, including those with music lessons, that are consistent with their predispositions; such environments exaggerate preexisting individual differences.

Music training relates to the development of neural mechanisms of selective auditory attention

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Does music training shape the development of neural mechanisms of auditory attention?

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We compared cortical responses to attended speech in child and adult musicians and nonmusicians.

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Musician children and adults had less prefrontal auditory response variability during attention.

Selective attention decreases trial-to-trial variability in cortical auditory-evoked activity. This effect increases over the course of maturation, potentially reflecting the gradual development of selective attention and inhibitory control. Work in adults indicates that music training may alter the development of this neural response characteristic, especially over brain regions associated with executive control: in adult musicians, attention decreases variability in auditory-evoked responses recorded over prefrontal cortex to a greater extent than in nonmusicians. We aimed to determine whether this musician-associated effect emerges during childhood, when selective attention and inhibitory control are under development. We compared cortical auditory-evoked variability to attended and ignored speech streams in musicians and nonmusicians across three age groups: preschoolers, school-aged children and young adults. Results reveal that childhood music training is associated with reduced auditory-evoked response variability recorded over prefrontal cortex during selective auditory attention in school-aged child and adult musicians. Preschoolers, on the other hand, demonstrate no impact of selective attention on cortical response variability and no musician distinctions. This finding is consistent with the gradual emergence of attention during this period and may suggest no pre-existing differences in this attention-related cortical metric between children who undergo music training and those who do not.

Engagement in community music classes sparks neuroplasticity and language development in children from disadvantaged backgrounds

Children from disadvantaged backgrounds often face impoverished auditory environments, such as greater exposure to ambient noise and fewer opportunities to participate in complex language interactions during development. These circumstances increase their risk for academic failure and dropout. Given the academic and neural benefits associated with musicianship, music training may be one method for providing auditory enrichment to children from disadvantaged backgrounds. We followed a group of primary-school students from gang reduction zones in Los Angeles, CA, USA for 2 years as they participated in Harmony Project. By providing free community music instruction for disadvantaged children, Harmony Project promotes the healthy development of children as learners, the development of children as ambassadors of peace and understanding, and the development of stronger communities. Children who were more engaged in the music program-as defined by better attendance and classroom participation-developed stronger brain encoding of speech after 2 years than their less-engaged peers in the program. Additionally, children who were more engaged in the program showed increases in reading scores, while those less engaged did not show improvements. The neural gains accompanying music engagement were seen in the very measures of neural speech processing that are weaker in children from disadvantaged backgrounds. Our results suggest that community music programs such as Harmony Project provide a form of auditory enrichment that counteracts some of the biological adversities of growing up in poverty, and can further support community-based interventions aimed at improving child health and wellness.

The medium helps the message: Early sensitivity to auditory fluency in children's endorsement of statements

Recently, a growing number of studies have investigated the cues used by children to selectively accept testimony. In parallel, several studies with adults have shown that the fluency with which information is provided influences message evaluation: adults evaluate fluent information as more credible than dysfluent information. It is therefore plausible that the fluency of a message could also influence children's endorsement of statements. Three experiments were designed to test this hypothesis with 3- to 5-year-olds where the auditory fluency of a message was manipulated by adding different levels of noise to recorded statements. The results show that 4 and 5-year-old children, but not 3-year-olds, are more likely to endorse a fluent statement than a dysfluent one. The present study constitutes a first attempt to show that fluency, i.e., ease of processing, is recruited as a cue to guide epistemic decision in children. An interpretation of the age difference based on the way cues are processed by younger children is suggested.

Auditory reserve and the legacy of auditory experience

Musical training during childhood has been linked to more robust encoding of sound later in life. We take this as evidence for an auditory reserve: a mechanism by which individuals capitalize on earlier life experiences to promote auditory processing. We assert that early auditory experiences guide how the reserve develops and is maintained over the lifetime. Experiences that occur after childhood, or which are limited in nature, are theorized to affect the reserve, although their influence on sensory processing may be less long-lasting and may potentially fade over time if not repeated. This auditory reserve may help to explain individual differences in how individuals cope with auditory impoverishment or loss of sensorineural function.

Auditory learning through active engagement with sound: biological impact of community music lessons in at-risk children

The young nervous system is primed for sensory learning, facilitating the acquisition of language and communication skills. Social and linguistic impoverishment can limit these learning opportunities, eventually leading to language-related challenges such as poor reading. Music training offers a promising auditory learning strategy by directing attention to meaningful acoustic elements of the soundscape. In light of evidence that music training improves auditory skills and their neural substrates, there are increasing efforts to enact community-based programs to provide music instruction to at-risk children. Harmony Project is a community foundation that has provided free music instruction to over 1000 children from Los Angeles gang-reduction zones over the past decade. We conducted an independent evaluation of biological effects of participating in Harmony Project by following a cohort of children for 1 year. Here we focus on a comparison between students who actively engaged with sound through instrumental music training vs. students who took music appreciation classes. All children began with an introductory music appreciation class, but midway through the year half of the children transitioned to the instrumental training. After the year of training, the children who actively engaged with sound through instrumental music training had faster and more robust neural processing of speech than the children who stayed in the music appreciation class, observed in neural responses to a speech sound /d/. The neurophysiological measures found to be enhanced in the instrumentally-trained children have been previously linked to reading ability, suggesting a gain in neural processes important for literacy stemming from active auditory learning. Despite intrinsic constraints on our study imposed by a community setting, these findings speak to the potential of active engagement with sound (i.e., music-making) to engender experience-dependent neuroplasticity and may inform the development of strategies for auditory learning.

Environmental acoustic enrichment promotes recovery from developmentally degraded auditory cortical processing

It has previously been shown that environmental enrichment can enhance structural plasticity in the brain and thereby improve cognitive and behavioral function. In this study, we reared developmentally noise-exposed rats in an acoustic-enriched environment for ∼4 weeks to investigate whether or not enrichment could restore developmentally degraded behavioral and neuronal processing of sound frequency. We found that noise-exposed rats had significantly elevated sound frequency discrimination thresholds compared with age-matched naive rats. Environmental acoustic enrichment nearly restored to normal the behavioral deficit resulting from early disrupted acoustic inputs. Signs of both degraded frequency selectivity of neurons as measured by the bandwidth of frequency tuning curves and decreased long-term potentiation of field potentials recorded in the primary auditory cortex of these noise-exposed rats also were reversed partially. The observed behavioral and physiological effects induced by enrichment were accompanied by recovery of cortical expressions of certain NMDA and GABAA receptor subunits and brain-derived neurotrophic factor. These studies in a rodent model show that environmental acoustic enrichment promotes recovery from early noise-induced auditory cortical dysfunction and indicate a therapeutic potential of this noninvasive approach for normalizing neurological function from pathologies that cause hearing and associated language impairments in older children and adults.

Biological impact of auditory expertise across the life span: musicians as a model of auditory learning

Experience-dependent characteristics of auditory function, especially with regard to speech-evoked auditory neurophysiology, have garnered increasing attention in recent years. This interest stems from both pragmatic and theoretical concerns as it bears implications for the prevention and remediation of language-based learning impairment in addition to providing insight into mechanisms engendering experience-dependent changes in human sensory function. Musicians provide an attractive model for studying the experience-dependency of auditory processing in humans due to their distinctive neural enhancements compared to nonmusicians. We have only recently begun to address whether these enhancements are observable early in life, during the initial years of music training when the auditory system is under rapid development, as well as later in life, after the onset of the aging process. Here we review neural enhancements in musically trained individuals across the life span in the context of cellular mechanisms that underlie learning, identified in animal models. Musicians' subcortical physiologic enhancements are interpreted according to a cognitive framework for auditory learning, providing a model in which to study mechanisms of experience-dependent changes in human auditory function.

The layering of auditory experiences in driving experience-dependent subcortical plasticity

In this review article, we focus on recent studies of experiential influences on brainstem function. Using these studies as scaffolding, we then lay the initial groundwork for the Layering Hypothesis, which explicates how experiences combine to shape subcortical auditory function. Our hypothesis builds on the idea that the subcortical auditory system reflects the collective auditory experiences of an individual, including interactions with sound that occurred in the distant past. Our goal for this article is to begin to shift the field away from examining the effect of single experiences to examining how different auditory experiences layer or superimpose on each other. This article is part of a Special Issue entitled <Annual Reviews 2014>.

High school music classes enhance the neural processing of speech

Should music be a priority in public education? One argument for teaching music in school is that private music instruction relates to enhanced language abilities and neural function. However, the directionality of this relationship is unclear and it is unknown whether school-based music training can produce these enhancements. Here we show that 2 years of group music classes in high school enhance the neural encoding of speech. To tease apart the relationships between music and neural function, we tested high school students participating in either music or fitness-based training. These groups were matched at the onset of training on neural timing, reading ability, and IQ. Auditory brainstem responses were collected to a synthesized speech sound presented in background noise. After 2 years of training, the neural responses of the music training group were earlier than at pre-training, while the neural timing of students in the fitness training group was unchanged. These results represent the strongest evidence to date that in-school music education can cause enhanced speech encoding. The neural benefits of musical training are, therefore, not limited to expensive private instruction early in childhood but can be elicited by cost-effective group instruction during adolescence.

Art and science: how musical training shapes the brain

What makes a musician? In this review, we discuss innate and experience-dependent factors that mold the musician brain in addition to presenting new data in children that indicate that some neural enhancements in musicians unfold with continued training over development. We begin by addressing effects of training on musical expertise, presenting neural, perceptual, and cognitive evidence to support the claim that musicians are shaped by their musical training regimes. For example, many musician-advantages in the neural encoding of sound, auditory perception, and auditory-cognitive skills correlate with their extent of musical training, are not observed in young children just initiating musical training, and differ based on the type of training pursued. Even amidst innate characteristics that contribute to the biological building blocks that make up the musician, musicians demonstrate further training-related enhancements through extensive education and practice. We conclude by reviewing evidence from neurobiological and epigenetic approaches to frame biological markers of musicianship in the context of interactions between genetic and experience-related factors.

Musical training heightens auditory brainstem function during sensitive periods in development

Experience has a profound influence on how sound is processed in the brain. Yet little is known about how enriched experiences interact with developmental processes to shape neural processing of sound. We examine this question as part of a large cross-sectional study of auditory brainstem development involving more than 700 participants, 213 of whom were classified as musicians. We hypothesized that experience-dependent processes piggyback on developmental processes, resulting in a waxing-and-waning effect of experience that tracks with the undulating developmental baseline. This hypothesis led to the prediction that experience-dependent plasticity would be amplified during periods when developmental changes are underway (i.e., early and later in life) and that the peak in experience-dependent plasticity would coincide with the developmental apex for each subcomponent of the auditory brainstem response (ABR). Consistent with our predictions, we reveal that musicians have heightened response features at distinctive times in the life span that coincide with periods of developmental change. The effect of musicianship is also quite specific: we find that only select components of auditory brainstem activity are affected, with musicians having heightened function for onset latency, high-frequency phase-locking, and response consistency, and with little effect observed for other measures, including lower-frequency phase-locking and non-stimulus-related activity. By showing that musicianship imparts a neural signature that is especially evident during childhood and old age, our findings reinforce the idea that the nervous system's response to sound is “chiseled” by how a person interacts with his specific auditory environment, with the effect of the environment wielding its greatest influence during certain privileged windows of development.

Neural sensitivity to statistical regularities as a fundamental biological process that underlies auditory learning: the role of musical practice

There is increasing evidence that humans and other nonhuman mammals are sensitive to the statistical structure of auditory input. Indeed, neural sensitivity to statistical regularities seems to be a fundamental biological property underlying auditory learning. In the case of speech, statistical regularities play a crucial role in the acquisition of several linguistic features, from phonotactic to more complex rules such as morphosyntactic rules. Interestingly, a similar sensitivity has been shown with non-speech streams: sequences of sounds changing in frequency or timbre can be segmented on the sole basis of conditional probabilities between adjacent sounds. We recently ran a set of cross-sectional and longitudinal experiments showing that merging music and speech information in song facilitates stream segmentation and, further, that musical practice enhances sensitivity to statistical regularities in speech at both neural and behavioral levels. Based on recent findings showing the involvement of a fronto-temporal network in speech segmentation, we defend the idea that enhanced auditory learning observed in musicians originates via at least three distinct pathways: enhanced low-level auditory processing, enhanced phono-articulatory mapping via the left Inferior Frontal Gyrus and Pre-Motor cortex and increased functional connectivity within the audio-motor network. Finally, we discuss how these data predict a beneficial use of music for optimizing speech acquisition in both normal and impaired populations.

Function and plasticity of the medial olivocochlear system in musicians: a review

The outer hair cells of the organ of Corti are the target of abundant efferent projections from the olivocochlear system. This peripheral efferent auditory subsystem is currently thought to be modulated by central activity via corticofugal descending auditory system, and to modulate active cochlear micromechanics. Although the function of this efferent subsystem remains unclear, physiological, psychophysical, and modeling data suggest that it may be involved in ear protection against noise damage and auditory perception, especially in the presence of background noise. Moreover, there is mounting evidence that its activity is modulated by auditory and visual attention. A commonly used approach to measure olivocochlear activity noninvasively in humans relies on the suppression of otoacoustic emissions by contralateral noise. Previous studies have found substantial interindividual variability in this effect, and statistical differences have been observed between professional musicians and non-musicians, with stronger bilateral suppression effects in the former. In this paper, we review these studies and discuss various possible interpretations for these findings, including experience-dependent neuroplasticity. We ask whether differences in olivocochlear function between musicians and non-musicians reflect differences in peripheral auditory function or in more central factors, such as top-down attentional modulation.