The neural control of volitional vocal production—from speech to identity, from social meaning to song

Abstract

The networks of cortical and subcortical fields that contribute to speech production have benefitted from many years of detailed study, and have been used as a framework for human volitional vocal production more generally. In this article, I will argue that we need to consider speech production as an expression of the human voice in a more general sense. I will also argue that the neural control of the voice can and should be considered to be a flexible system, into which more right hemispheric networks are differentially recruited, based on the factors that are modulating vocal production. I will explore how this flexible network is recruited to express aspects of non-verbal information in the voice, such as identity and social traits. Finally, I will argue that we need to widen out the kinds of vocal behaviours that we explore, if we want to understand the neural underpinnings of the true range of sound-making capabilities of the human voice. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part II)’.

Laughter and culture

“…Volitional control of speech articulators, operating through direct neural projections between motor cortex and laryngeal musculature, affords the production of complex, rapidly generated phonetic sounds useful for language [7,9]. And the volitional control of articulators allows speakers to imitate other kinds of sounds in our environment [10,11].…”

Robert Provine: the critical human importance of laughter, connections and contagion

“…Laughter is rich in information: adult listeners can distinguish between spontaneous and communicative laughter [ 9 ], and listeners can determine how close two talkers are by the sound of their laughter [ 10 ]. Listeners can also tell two talkers apart from their communicative laughter, but not their spontaneous laughter [ 11 ], suggesting that communicative laughter may be controlled (at least in part) via the volitional speech motor network [ 12 ], while spontaneous laughter may be controlled entirely by the evolutionarily older involuntary vocalization network. In reality, much naturally occurring laughter is likely to be a mix of both types [ 13 ].…”

Form follows function in human nonverbal vocalisations

“…Flexibility in vocal production has also been observed in other great ape species, including wild bonobos (Clay et al 2015;Cornec et al in press) and both wild and enculturated orangutans (Lameira et al 2013a(Lameira et al , 2013b. Research emerging in the past decade is also challenging the traditional dualpathway model of vocal control in mammals, pointing to a greater degree of cross-talk between the cortical and limbic pathways typically thought to be respectively involved in volitional and spontaneous vocal production (e.g., Ludlow 2015;Wattendorf et al 2013;reviewed in Ackermann et al 2014, Pisanski et al 2016, and Scott 2021.…”