Convergence of calls as animals form social bonds, active compensation for noisy communication channels, and the evolution of vocal learning in mammals

Author Posting. © American Psychological Association, 2008. This is the author's version of the work. It is posted here by permission of American Psychological Association for personal use, not for redistribution. The definitive version was published in Journal of Comparative Psychology 122 (2008): 319-331, doi:10.1037/a0013087.The classic evidence for vocal production learning involves imitation of novel, often anthropogenic sounds. Among mammals, this has been reported for African elephants, harbor seals, and dolphins. A broader taxonomic distribution has been reported for vocal convergence, where the acoustic properties of calls from different individuals converge when they are housed together in captivity or form social bonds in the wild. This kind of vocal convergence has been demonstrated for animals as diverse as songbirds, parakeets, bats, elephants, cetaceans, and primates. For most of these species, call convergence is thought to reflect a group-distinctive identifier, with shared calls reflecting and strengthening social bonds. Pooling data on vocal imitation and vocal convergence suggests a wider taxonomic distribution of vocal production learning among mammals than generally appreciated. The wide taxonomic distribution of this evidence for vocal production learning suggests that perhaps more of the neural underpinnings for vocal production learning are in place in mammals than is usually imagined. One ubiquitous function for vocal production learning that is starting to receive attention involves modifying signals to improve communication in a noisy channel

Bi-phonic voice: a study of the potential for using the extended vibrational qualities of overtone chanting and singing as an intervention in training the speaking voice

Research report submitted in partial fulfilment of the requirements for the degree of Master of Arts by Coursework and research report School of Arts, Drama Division University of the Witwatersrand, Johannesburg, South AfricaThis study examines human vocal production through the lens of vibration. The needs of the speaking voice in terms of communication are explored, with particular emphasis on the vocal needs of the professional speaker, where extended range and resonance will ensure optimum communicative effect. As this goal may require training, a comparative study is presented of approaches to vocal training that have the aim of improving resonance and range while minimising damage to the vocal apparatus. These approaches include the quest to overcome physical, societal and emotional blocks to effective vocal production. This comparative study is based on the writings of a selection of popular vocal training theorists’ writings. To enhance the study of effective vocal production, the physical and physiological means of meeting the needs of producing voice are explored, by an interrogation of what vibration is in terms of vocal production. To investigate this, I have examined the physical nature of vibration, followed by the physiological aspect of this vibration as it relates to vocal production. Included in this investigation is an appreciation of what might affect the vibrations of speech that relate to resonance and range, to either enhance or hinder them. Because Bi-phonic voice, or Overtone singing and chanting, uses extended vibrational qualities, this study explores the possibility of using these vibrational qualities in vocal training to extend range and resonance. A brief ethnological study of Bi-phonic voice is presented followed by an examination of its functioning with emphasis on the manner in which the vibrations used may differ from those in western vocal techniques. Experiential reports of Bi-phonic vocal production, obtained through interviews, are presented, which in conjunction with literature on the practice will contribute to ascertaining whether there is in fact potential for using the techniques, without endangering the vocal apparatus, as an adjunct to current vocal training trends

Vocal production learning in mammals revisited

Vocal production learning, the ability to modify the structure of vocalizations as a result of hearing those of others, has been studied extensively in birds but less attention has been given to its occurrence in mammals. We summarize the available evidence for vocal learning in mammals from the last 25 years, updating earlier reviews on the subject. The clearest evidence comes from cetaceans, pinnipeds, elephants and bats where species have been found to copy artificial or human language sounds, or match acoustic models of different sound types. Vocal convergence, in which parameter adjustments within one sound type result in similarities between individuals, occurs in a wider range of mammalian orders with additional evidence from primates, mole-rats, goats and mice. Currently, the underlying mechanisms for convergence are unclear with vocal production learning but also usage learning or matching physiological states being possible explanations. For experimental studies, we highlight the importance of quantitative comparisons of seemingly learned sounds with vocal repertoires before learning started or with species repertoires to confirm novelty. Further studies on the mammalian orders presented here as well as others are needed to explore learning skills and limitations in greater detail.Publisher PDFPeer reviewe

A case study investigating perceptions on process and outcomes in applying the Alexander Technique in vocal production

This case study investigated perceptions on process and outcomes of applying the Alexander Technique in vocal production. The setting was the campus of a state university in the United States of America. The perceptions of three levels of participants were investigated- a master Alexander Technique teacher, a collegiate vocal professor and three undergraduate music students, all experienced in the Alexander Technique in vocal production. Data collection included interviews with the participants; documentation in student practice journals, and field observations. Data were analyzed, determining consistent trends between all the participant\u27s perceptions of the processes involved in applying Alexander Technique in vocal production. These primarily involved improving body awareness through body mapping, identifying physical habits that cause tension, and replacing these with natural freedom in movement. Furthermore, there was parity in perceptions on positive outcomes in vocal production, including ability to sustain notes and increase the range, fullness and quality of the voice. Minor disparities were indicated between perceptions on process, such as specific psychological focus and reference to personality. Links were found between perceptions articulated in interviews, journals and field observations regarding both process and outcomes. The results provide valuable knowledge that, alongside other similar studies, may inform the music education profession --Document

Are eyebrow movements linked to voice variations and turn-taking? An experimental investigation

International audienceFollowing our work on the relationship between eyebrow movements and the fundamental frequency of the voice, this article presents the results of a study on this phenomenon, and also on the temporal location of rapid eyebrow movements with respect to speaking turns during dialogue. We used an automatic movement-acquisition system coupled with the simultaneous, synchronized recording of the vocal production. This procedure permits an objective analysis of eyebrow movements in relation to the vocal production. The data obtained show that the speakers' rapid eyebrow movements were associated both with turn-taking (occurring on or before speaking turn onset) and with changes in the fundamental frequency. These findings suggest that rapid eyebrow movements are mainly linked to motivation and the intention to communicate, and may also act as a focus marker in speech

Vocalization-associated respiration patterns: thermography-based monitoring and detection of preparation for calling

Vocal emission requires coordination with the respiratory system. Monitoring the increase in laryngeal pressure, which is needed for vocal production, allows detection of transitions from quiet respiration to vocalization-supporting respiration. Characterization of these transitions could be used to identify preparation for vocal emission and to examine the probability of it manifesting into an actual vocal production event. Specifically, overlaying the subject's respiration with conspecific calls can highlight events of call initiation and suppression, as a means of signalling coordination and avoiding jamming. Here, we present a thermal imaging-based methodology for synchronized respiration and vocalization monitoring of free-ranging meerkats. The sensitivity of this methodology is sufficient for detecting transient changes in the subject's respiration associated with the exertion of vocal production. The differences in respiration are apparent not only during the vocal output, but also prior to it, marking the potential time frame of the respiratory preparation for calling. A correlation between conspecific calls with elongation of the focal subject's respiration cycles could be related to fluctuations in attention levels or in the motivation to reply. This framework can be used for examining the capability for enhanced respiration control in animals during modulated and complex vocal sequences, detecting ‘failed’ vocalization attempts and investigating the role of respiration cues in the regulation of vocal interactions

Why vocal production of atypical sounds in apes and its cerebral correlates have a lot to say about the origin of language

Ackermann et al. mentioned the "acquisition of species-atypical sounds" in apes without any discussions. In our commentary, we demonstrate that these atypical sounds in chimpanzees not only include laryngeal sounds but also have a major significance regarding the origins of language, if we consider looking at their context of use, their social properties, their relations with gestures, their lateralization and their neurofunctional correlates as well

Vocalization Induced CFos Expression in Marmoset Cortex

All non-human primates communicate with conspecifics using vocalizations, a system involving both the production and perception of species-specific vocal signals. Much of the work on the neural basis of primate vocal communication in cortex has focused on the sensory processing of vocalizations, while relatively little data are available for vocal production. Earlier physiological studies in squirrel monkeys had shed doubts on the involvement of primate cortex in vocal behaviors. The aim of the present study was to identify areas of common marmoset (Callithrix jacchus) cortex that are potentially involved in vocal communication. In this study, we quantified cFos expression in three areas of marmoset cortex – frontal, temporal (auditory), and medial temporal – under various vocal conditions. Specifically, we examined cFos expression in these cortical areas during the sensory, motor (vocal production), and sensory–motor components of vocal communication. Our results showed an increase in cFos expression in ventrolateral prefrontal cortex as well as the medial and lateral belt areas of auditory cortex in the vocal perception condition. In contrast, subjects in the vocal production condition resulted in increased cFos expression only in dorsal premotor cortex. During the sensory–motor condition (antiphonal calling), subjects exhibited cFos expression in each of the above areas, as well as increased expression in perirhinal cortex. Overall, these results suggest that various cortical areas outside primary auditory cortex are involved in primate vocal communication. These findings pave the way for further physiological studies of the neural basis of primate vocal communication