Singers show enhanced performance and neural representation of vocal imitation

Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal expertise, using an imitation task that required adjustments of larynx musculature during speech. Highly trained human singers and non-singer control participants modulated voice pitch and vocal tract length (VTL) to mimic auditory speech targets, while undergoing real-time anatomical scans of the vocal tract and functional scans of brain activity. Multivariate analyses of speech acoustics, larynx movements and brain activation data were used to quantify vocal modulation behaviour and to search for neural representations of the two modulated vocal parameters during the preparation and execution of speech. We found that singers showed more accurate task-relevant modulations of speech pitch and VTL (i.e. larynx height, as measured with vocal tract MRI) during speech imitation; this was accompanied by stronger representation of VTL within a region of the right somatosensory cortex. Our findings suggest a common neural basis for enhanced vocal control in speech and song. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’.

Singers and non-singers differ in the performance and neural representation of vocal imitation

Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal expertise, using an imitation task that required adjustments of larynx musculature during speech. Highly-trained human singers and non-singer control participants modulated voice pitch and vocal tract length (VTL) to mimic auditory speech targets, while undergoing real-time anatomical scans of the vocal tract and functional scans of brain activity. Multivariate analyses of speech acoustics, larynx movements and brain activation data were used to quantify vocal modulation behaviour, and to search for neural representations of the two modulated vocal parameters during the preparation and execution of speech. We found that singers showed more accurate task-relevant modulations of speech pitch and VTL (i.e. larynx height, as measured with vocal tract MRI) during speech imitation; this was accompanied by stronger representation of VTL within a region of right dorsal somatosensory cortex. Our findings suggest a common neural basis for enhanced vocal control in speech and song.

Comparing Phonetic Convergence in Children and Adults

Observations by sociolinguists suggest that when children relocate to a new community, they rapidly learn to imitate their peers, adopting the new local accent faster and more effectively than adults. However, few well-controlled laboratory experiments have been conducted comparing speech or accent imitation across ages. Here, we investigated Canadian English-speaking children’s and adults’ imitation of three model speakers: a Canadian English talker, an Australian English talker, and a non-native Mandarin English talker who learned English later in life. The speech of all three talkers was manipulated to have elongated voice onset time (VOT) on word initial stop consonants. The dependent measure was how much participants would lengthen their VOTs after exposure to one of the talkers in two paradigms: delayed shadowing (Experiment 1) and immediate shadowing (Experiment 2). We predicted that overall children would show more imitation than adults, particularly when imitating the Canadian English talker, given previous work on children’s social preferences. Although we did not observe age differences in either study, when shadowing was immediate, we found that imitation was influenced by the accent of the speaker, but not in the manner we predicted: both age groups imitated the Mandarin-accented model more strongly than the Canadian model. When shadowing was delayed, we observed no evidence of imitation. We discuss our findings in light of other recent work, and conclude that the development of speech imitation is an area ripe for further investigation.

Brain, musicality and language aptitude: A complex interplay

Music and language are highly intertwined auditory phenomena that largely overlap on behavioral and neural levels. While the link between the two has been widely explored on a general level, comparably few studies have addressed the relationship between musical skills and language aptitude, defined as an individual's (partly innate) capacity for learning foreign languages. Behaviorally, past research has provided evidence that individuals’ musicality levels (expressed by singing, instrument playing, and/or perceptive musical abilities) are significantly associated with their foreign language learning, particularly the acquisition of phonetic and phonological skills (e.g., pronunciation, speech imitation). On the neural level, both skills recruit a wide array of overlapping brain areas, which are also involved in cognition and memory. The neurobiology of language aptitude is an area ripe for investigation, since there has been only limited research establishing neurofunctional and neuroanatomical markers characteristic of speech imitation and overall language aptitude (e.g., in the left/right auditory cortex and left inferior parietal areas of the brain). Thus, as noted above, in this short review for ARAL, the aim is to describe the most recent neuroscientific findings on the neurobiology of language aptitude, to discuss the complex interplay between language aptitude and musicality from neural and behavioral perspectives, and to briefly outline what the promise of future research in this area holds.

Early Influence of Musical Abilities and Working Memory on Speech Imitation Abilities: Study with Pre-School Children

Musical aptitude and language talent are highly intertwined when it comes to phonetic language ability. Research on pre-school children’s musical abilities and foreign language abilities are rare but give further insights into the relationship between language and musical aptitude. We tested pre-school children’s abilities to imitate unknown languages, to remember strings of digits, to sing, to discriminate musical statements and their intrinsic (spontaneous) singing behavior (“singing-lovers versus singing nerds”). The findings revealed that having an ear for music is linked to phonetic language abilities. The results of this investigation show that a working memory capacity and phonetic aptitude are linked to high musical perception and production ability already at around the age of 5. This suggests that music and (foreign) language learning capacity may be linked from childhood on. Furthermore, the findings put emphasis on the possibility that early developed abilities may be responsible for individual differences in both linguistic and musical performances.