Vocal Development Research Articles

Neuronal Intrinsic Physiology Changes During Development of a Learned Behavior.

Juvenile male zebra finches learn their songs over distinct auditory and sensorimotor stages, the former requiring exposure to an adult tutor song pattern. The cortical premotor nucleus HVC (acronym is name) plays a necessary role in both learning stages, as well as the production of adult song. Consistent with neural network models where synaptic plasticity mediates developmental forms of learning, exposure to tutor song drives changes in the turnover, density, and morphology of HVC synapses during vocal development. A network's output, however, is also influenced by the intrinsic properties (e.g., ion channels) of the component neurons, which could change over development. Here, we use patch clamp recordings to show cell-type-specific changes in the intrinsic physiology of HVC projection neurons as a function of vocal development. Developmental changes in HVC neurons that project to the basal ganglia include an increased voltage sag response to hyperpolarizing currents and an increased rebound depolarization following hyperpolarization. Developmental changes in HVC neurons that project to vocal-motor cortex include a decreased resting membrane potential and an increased spike amplitude. HVC interneurons, however, show a relatively stable range of intrinsic features across vocal development. We used mathematical models to deduce possible changes in ionic currents that underlie the physiological changes and to show that the magnitude of the observed changes could alter HVC circuit function. The results demonstrate developmental plasticity in the intrinsic physiology of HVC projection neurons and suggest that intrinsic plasticity may have a role in the process of song learning.

From crying to word production – observational study of an identical twin pair with severe hearing disorder

ABSTRACTBackground: There is overwhelming evidence that auditory processing plays an important role at the beginning of language development. This contradicts long held opinion by some researchers and parents that early vocal development is innate and does not require auditory input. Consequently, vocalizations such as cooing or pre-canonical babbling do not deviate in sensory-neural hearing impaired infants.Method: Here we report twin data to contribute to this debate. Using repeated recordings of comfort utterances over the first 20 months, we objectively determined and compared the course of vocal development of a healthy identical twin pair with a profound neuro-sensory hearing disorder.Results: Recordings four weeks after CI activation demonstrated an interesting phenomenon: vocal utterances seemed to re-vitalize primitive elements, i.e., we observed an apparent vocal ‘regression’.Conclusion: The higher cognitive level of the 10-months-old girls at cochlear implantation compared to younger infants together with the more mature neural network for language development might be the essential reason for the quicker second passing of vocal stages.

Emergent Jaw Predominance in Vocal Development Through Stochastic Optimization

Infant vocal babbling strongly relies on jaw oscillations, especially at the stage of canonical babbling, which underlies the syllabic structure of world languages. In this paper, we propose, model and analyze an hypothesis to explain this predominance of the jaw in early babbling. This hypothesis states that general stochastic optimization principles, when applied to learning sensorimotor control, automatically generate ordered babbling stages with a predominant exploration of jaw movements in early stages. The reason is that those movements impact the auditory effects more than other articulators. In previous computational models, such general principles were shown to selectively freeze and free degrees of freedom in a model reproducing the proximo-distal development observed in infant arm reaching. The contribution of this paper is to show how, using the same methods, we are able to explain such patterns in vocal development. We present three experiments. The two first ones show that the recruitment order of articulators emerging from stochastic optimization depends on the target sound to be achieved but that on average the jaw is largely chosen as the first recruited articulator. The third experiment analyses in more detail how the emerging recruitment order is shaped by the dynamics of the optimization process.

Picture Exchange Communication System and Delay to Reinforcement

Picture Exchange Communication Systems (PECS) is a form of augmentative and alternative communication (AAC) frequently used by individuals with autism spectrum disorder and intellectual disability when speech development is delayed or does not develop (Bondy and Frost 1994 in Focus on Autism and Other Developmental Disabilities, 9, 1–19; Sunberg and Partington 1998). Researchers have previously evaluated variations of PECS as a means for vocalization development (Ganz and Simpson 2004 in Journal of Autism and Developmental Disorders, 34, 395–409; Tincani et al. 2006 in Education and Training in Developmental Disabilities, 41, 177–184). The current study investigated delay to reinforcement and an increase in response effort when utilizing PECS on the development of intelligible word vocalizations with four elementary aged students. Three participants transitioned from primarily requesting using PECS at Phase IIIb to using independent vocalizations (i.e., spoken words). This research provides further evidence for the use of PECS not only as a tool for functional communication, but also as a resource for assisting individuals in the development of vocalizations with slight variations in the parameters of reinforcement including response effort and delay of reinforcement.

Evidence for Dialects in Three Captive Populations of Common Marmosets (Callithrix jacchus)

The vocal repertoires of nonhuman primates have long been thought to be invariable across populations and not to result from vocal learning. However, increasing evidence suggests that learning does influence vocal production in nonhuman primates, and that several species modify the structure of their calls in response to social or environmental influences. Vocal usage learning refers to the process whereby an individual learns in which circumstances to produce a certain call type, whereas vocal production learning refers to the process in which signals get modified as the result of individual experiences. Common marmosets (Callithrix jacchus) show socially mediated vocal plasticity as adults and during vocal development. This propensity to engage in simple forms of vocal production learning (accommodation) should produce population-level differences in call structure. To test this prediction, we compared the vocalizations of three captive populations of common marmosets. We analyzed the acoustic structure of 1337 phee calls, 461 trills, and 3611 food calls and compared them with a permutated discriminant function analysis. We found that all call types differed significantly between the three populations, and 76–98% of the calls were correctly classified. As physical differences in body mass and environmental differences between colonies could not explain the call differences, we conclude that vocal accommodation is the most likely explanation for the differences in call structure. This will allow us to further investigate the role and importance of vocal learning in a species increasingly used to study vocal learning and language evolution.

Chronic CB1 cannabinoid receptor antagonism persistently increases dendritic spine densities in brain regions important to zebra finch vocal learning and production in an antidepressant-sensitive manner

During typical late-postnatal CNS development, net reductions in dendritic spine densities are associated with activity-dependent learning. Prior results showed agonist exposure in young animals increased spine densities in a subset of song regions while adult exposures did not, suggesting endocannabinoid signaling regulates dendritic spine dynamics important to vocal development. Here we addressed this question using the CB1 receptor-selective antagonist SR141716A (SR) to disrupt endocannabinoid signaling both during and after vocal learning. We hypothesized antagonist exposure during vocal development, but not adulthood, would alter spine densities. Following 25days of exposure and a 25day maturation period, 3D reconstructions of Golgi-Cox stained neurons were used to measure spine densities. We found antagonist treatments during both age periods increased densities within Area X (basal ganglia) and following adult treatments within HVC (premotor cortical-like). Results suggest both inappropriate cannabinoid receptor stimulation and inhibition are capable of similar disregulatory effects during establishment of circuits important to vocal learning, with antagonism extending these effects through adulthood. Given clinical evidence of depressant effects of SR, we tested the ability of the antidepressant monoamine oxidase inhibitor (MAOI) phenelzine to mitigate SR-induced spine density increases. This was confirmed implicating interaction between monoamine and endocannabinoid systems. Finally, we evaluated acute effects of these drugs to alter ability of novel song exposure to increase spine densities in auditory NCM and other regions, finding when combined, SR and phenelzine increased densities within Area X. These results contribute to understanding relevance of dendritic spine dynamics in neuronal development, drug abuse, and depression.

Automated Assessment of Child Vocalization Development Using LENA.

To produce a novel, efficient measure of children's expressive vocal development on the basis of automatic vocalization assessment (AVA), child vocalizations were automatically identified and extracted from audio recordings using Language Environment Analysis (LENA) System technology. Assessment was based on full-day audio recordings collected in a child's unrestricted, natural language environment. AVA estimates were derived using automatic speech recognition modeling techniques to categorize and quantify the sounds in child vocalizations (e.g., protophones and phonemes). These were expressed as phone and biphone frequencies, reduced to principal components, and inputted to age-based multiple linear regression models to predict independently collected criterion-expressive language scores. From these models, we generated vocal development AVA estimates as age-standardized scores and development age estimates. AVA estimates demonstrated strong statistical reliability and validity when compared with standard criterion expressive language assessments. Automated analysis of child vocalizations extracted from full-day recordings in natural settings offers a novel and efficient means to assess children's expressive vocal development. More research remains to identify specific mechanisms of operation.

Profiles of vocal development in Korean children with and without cleft palate

ABSTRACTThis study longitudinally investigated vocal development in Korean children from 9 to 18 months of age with and without cleft palate (CP). Utterance samples were collected from 24 children with and without CP at 9, 12, 15 and 18 months of age. Each utterance was categorised into levels of vocalisation using the Korean-translated version of the Stark Assessment of Early Vocal Development-Revised (SAEVD-R). The results showed children with CP produced a significantly higher rate of precanonical vocalisations (the combination of Levels 1, 2, and 3) and a lower rate of Level 4 and 5 vocalisations than children without CP. Both groups showed decreases in Levels 1 and 2 and increases in Level 5 from 9 to 18 months of age. A significant increase in the proportion of Level 4 vocalisations across age was observed only in children without CP. Young Korean children with CP showed lower proportions of advanced vocalisation levels characterised by canonical and complex syllable structures across 9 and 18 months of age compared to children without CP.

Age-dependent change in attention paid to vocal exchange rules in Japanese macaques

The mechanisms underlying vocal development in nonhuman primates, so-called ‘nonlearners’, are of special interest because they give an insight in how social factors can shape the expression of an already genetically determined vocal repertoire. Interestingly, recent studies suggest that the acquisition of the complex rules governing vocal exchanges (i.e. context-specific temporal and structural acoustic adjustments) may result from a socially guided development process, with social experience and parental selective feedback playing a key role. Among those conversational rules, call matching is a particularly remarkable phenomenon in Japanese macaques, Macaca fuscata, with interacting adult females matching the frequency range pattern of their own call with another female's preceding call. Here, we investigated whether fine-tuned acoustic adjustments during vocal exchanges in Japanese macaques are subject to developmental processes, specifically testing for the ability of individuals of different age classes to discriminate between vocal exchanges respecting, or not, the matching rule. We performed playback experiments in 10 adult and 10 1-year-old captive Japanese macaque females. Each subject was successively exposed to two stimuli: a pair of calls respecting call matching (i.e. two calls from two individuals with matched frequency ranges) and another pair of calls that did not. Adults discriminated better than juveniles whether stimuli respected the call-matching rule or not, and displayed significantly different levels of interest towards each stimulus type. The latency to look towards the loudspeaker was shorter, and the duration of the directed gaze was longer, after the playback that violated the matching expectation in every adult, but not in juveniles which seemingly displayed a random gaze response. Our findings support the conclusion that the matching rule is relevant for adults, but not for socially inexperienced young monkeys which may not have had enough experience of the conversational rules governing vocal exchanges.

鳴禽類の音声発達と多様牲の起源( 音によるコミュニケーション:その進化と個体発達)

鳴禽類の音声発達と多様牲の起源( 音によるコミュニケーション:その進化と個体発達)

言語獲得の基盤としての乳児の音声発達 (話す仕組みを巡って : 発話機構研究の最前線)

言語獲得の基盤としての乳児の音声発達 (話す仕組みを巡って : 発話機構研究の最前線)

Vocal Learning via Social Reinforcement by Infant Marmoset Monkeys

For over half a century now, primate vocalizations have been thought to undergo little or no experience-dependent acoustic changes during development [1]. If any changes are apparent, then they are routinely (and quite reasonably) attributed to the passive consequences of growth. Indeed, previous experiments on squirrel monkeys and macaque monkeys showed that social isolation [2, 3], deafness [2], cross-fostering [4] and parental absence [5] have little or no effect on vocal development. Here, we explicitly test in marmoset monkeys-a very vocal and cooperatively breeding species [6]-whether the transformation of immature into mature contact calls by infants is influenced by contingent parental vocal feedback. Using a closed-loop design, we experimentally provided more versus less contingent vocal feedback to twin infant marmoset monkeys over their first 2months of life, the interval during which their contact calls transform from noisy, immature calls to tonal adult-like "phee" calls [7, 8]. Infants who received more contingent feedback had a faster rate of vocal development, producing mature-sounding contact calls earlier than the other twin. The differential rate of vocal development was not linked to genetics, perinatal experience, or body growth; nor did the amount of contingency influence the overall rate of spontaneous vocal production. Thus, we provide the first experimental evidence for production-related vocal learning during the development of a nonhuman primate.

Perceptual perseverance in a passerine with permanent papillar impairment

The Belgian Waterslager canary is unique for its loud, low-pitched song which is accompanied by a hereditary pathology involving missing and damaged hair cells in the basal end of the papilla. These birds were been bred for hundreds of years for loud, low-pitched song. Breeders likely selected for high frequency hearing loss. In spite hair cell regeneration, the papillae in these birds never approaches that of normal-hearing canaries. Auditory nerve and brainstem responses are also diminished, and auditory brainstem nuclei show reduced cell size. And these birds show a suite of psychoacoustic deficits consistent with impaired active processing as seen in humans with hearing loss. It is rather remarkable, then, that Belgian Waterslagers are able to learn, discriminate, and produce complex, species-specific sounds with such impaired frequency selectivity and phase processing. This feat, in the presence of severe peripheral auditory damage, underscores the importance of temporal information in the avian auditory perception and vocal learning. The obvious genetic basis of this pathology places the Belgian Waterslager canary in another unique position of being the only nonhuman organism which must navigate through vocal development and vocal learning in the face of an inherited developmental peripheral auditory pathology.

Differentiating infant cry from non-cry vocalizations based on perception of negativity and acoustic features

This study seeks to determine how human listeners discriminate cry vs. non-cry sounds by investigating acoustic factors that may contribute to the perception of negativity in infant vocalizations (e.g., cry, whine, and vowel-like sounds). The assumption is that identification of cry is self-evident; therefore, there has been no attempt to systematically differentiate cry from non-cry vocalizations. Twelve exemplars each of cry, whine, and vowel-like sound segments (36 total) were selected from archival audio recordings of infant vocalizations. Categories were selected from expert-judged audio signals of vocal development. Adult listeners identified each utterance as either cry, whine, or vowel-like sound as quickly and accurately as possible. They also judged the extent of negativity of each utterance. Acoustic features of each utterance were analyzed in association with the categories and degrees of negativity. Results suggest a continuum of negativity from cries (most negative) to vowel-like sounds (least negative), and that acoustic variables are gradated across the negativity continuum. However, preliminary results suggest that peak F0, peak RMS, and spectral slope best differentiate the categories.

Vocal behavior and ontogeny of Northern right whales in the southeast critical habitat

North Atlantic right whales are one of the most endangered of the great whales. A remnant population of ~500 inhabits the eastern seaboard of North America. A small fraction (2%) travels south to their critical calving habitat along the Florida and Georgia coast. By late November and through the winter, right whales give birth and nurse their calves in these shallow waters before departing in early spring to their northern habitats. In the southeast critical habitat mother-calf pairs remain generally isolated from other whales, presenting a unique platform to study vocal development and learning in large whales. Using small boats, GPS-instrumented, free-drifting autonomous acoustic buoys were deployed in close proximity to 44 photo-identified mother-calf pairs over 7 calving seasons. Surface video and synchronized underwater recordings documented their social and vocal behavior. With the exception of some low-energy gunshot sounds, mothers, and their calves, remained predominantly silent during the first 4 weeks. This might be due to calf maturation, and or a strategy to avoid harassment by other whales or potential predators. Over 100 calls have been analyzed from 15 different calves. Some of these calves were resampled at different stages at <1 week up to 12 weeks of age. Evidence of individual and age-related variance and changes in call structure, complexity, power, rates, as well as vocal mimicry are presented. [Funding: HBOI Florida PFW License Plate Fund, The Harry Richter Foundation and IBM, NOAA Permit #14233.]

Проблеми вокально-технічного розвитку майбутніх вчителів музики та шляхи їх подолання

The article highlights the problems of vocal and technical development of music teachers; their role in future artist’s mastering the skill of artistic performance of the vocal repertoire. Some fundamentally important features of the vocal and technical training of Italian vocal bel canto school singers, their understanding of the outstanding masters of vocal art and pedagogy of that time on the vocal technique and ways of its formation are considered. The role of psychophysiological studies, implemented in the 20 th century, in the development of modern vocal pedagogical science, in particular – concepts ofN. Bernstein’s theory of the movements biomechanics is revealed. Vocal and technical skills formation is considered as a complex process that is based oncoordination of all components of the singing and phonatory system: stature, respiration,articulatory and resonant components of sound formation. Acquired skill should not only be coordinated and automated, but also have some flexibility, turning into ability to apply it in various musical contexts. Peculiarities of singer’s virtuoso technique formation are analyzed; effective ways to improve their vocal agility while working on the vocal passages are justified. Typicalproblems accompanying the formation of virtuoso singing technique and methods for their overcoming, concerning phonatory problems, and singer’s metro-rhythmic auditory presentation development, capacity for emotional and volitional self-regulation are described. Students’ understanding of vocal skills formation and automatization technology peculiarities should contribute to the higher quality of the learning process and to achieving better results for the shorter amount of time. This is particularly important for musical and educational institution, as students vocal setting is one of the most important components in their training for the multifunctional activity of the future music teacher.

A Retrospective Video Analysis of Canonical Babbling and Volubility in Infants with Fragile X Syndrome at 9-12 Months of Age.

An infant's vocal capacity develops significantly during the first year of life. Research suggests early measures of pre-speech development, such as canonical babbling and volubility, can differentiate typical versus disordered development. This study offers a new contribution by comparing early vocal development in 10 infants with Fragile X syndrome and 14 with typical development. Results suggest infants with Fragile X syndrome produce fewer syllables and have significantly lower canonical babbling ratios compared to infants who are typically developing. Furthermore, the particular measures of babbling were strong predictors of group membership, adding evidence regarding the possible utility of these markers in early identification.

The effects of a short-term music program on preschool children’s executive functions

The purpose of this study was to examine the effects of a short-term preschool music program with creativity, bimanual gross motor training, and vocal development on preschool children’s inhibition. Inhibition is the key factor in preschool children’s executive functions development between 3–5 years. Thirty-six preschool children were randomly assigned to music or Lego training, a comparable control task. We administered neuropsychological measures pre- and post-training. Results of a repeated measures ANOVA on the Matching Familiar Figures Test (MFFT), a task requiring inhibition and visual discrimination, indicated a significant time by group interaction, with fewer errors committed post-training by the music group compared to controls. However, only a main effect of time was found for the second inhibition task, the Day/Night Stroop Task, a task requiring inhibition of a dominant verbal response. Music training in early childhood that includes an emphasis on bimanual coordination in gross motor movements may contribute to enhanced inhibition performance on complex tasks.

Vocal development in a Waddington landscape.

Vocal development is the adaptive coordination of the vocal apparatus, muscles, the nervous system, and social interaction. Here, we use a quantitative framework based on optimal control theory and Waddington's landscape metaphor to provide an integrated view of this process. With a biomechanical model of the marmoset monkey vocal apparatus and behavioral developmental data, we show that only the combination of the developing vocal tract, vocal apparatus muscles and nervous system can fully account for the patterns of vocal development. Together, these elements influence the shape of the monkeys' vocal developmental landscape, tilting, rotating or shifting it in different ways. We can thus use this framework to make quantitative predictions regarding how interfering factors or experimental perturbations can change the landscape within a species, or to explain comparative differences in vocal development across species.

Limiting parental feedback disrupts vocal development in marmoset monkeys

Vocalizations of human infants undergo dramatic changes across the first year by becoming increasingly mature and speech-like. Human vocal development is partially dependent on learning by imitation through social feedback between infants and caregivers. Recent studies revealed similar developmental processes being influenced by parental feedback in marmoset monkeys for apparently innate vocalizations. Marmosets produce infant-specific vocalizations that disappear after the first postnatal months. However, it is yet unclear whether parental feedback is an obligate requirement for proper vocal development. Using quantitative measures to compare call parameters and vocal sequence structure we show that, in contrast to normally raised marmosets, marmosets that were separated from parents after the third postnatal month still produced infant-specific vocal behaviour at subadult stages. These findings suggest a significant role of social feedback on primate vocal development until the subadult stages and further show that marmoset monkeys are a compelling model system for early human vocal development.