Vocal Learning and Songbirds: An Evolutionary Tale of Singing

Abstract

Vocal Learning and Songbirds: An Evolutionary Tale of Singing Heidi Moss Erickson (bio) MINDING THE GAP [Introduction to the "Minding the Gap" series. Research on the neurobiological underpinnings of vocalization is growing at a rapid pace. Scientists from varied disciplines contribute to this field, elucidating the process from such diverse angles as evolutionary biology, molecular biology, genetics, neuroscience, and psychology.1 Singing is one of our most complex behaviors, involving coordination of more than 100 muscles, integrating both our musical and linguistic selves. Influences are derived from a looped brain-body-environment continuum and serve as the foundation for vocalization and artistic expression. It is therefore essential that singers, pedagogues, and voice scientists capitalize on this wealth of data to fully understand our instruments. An integrative view of how and why we sing can refine the art of voice pedagogy, demystify long held myths, and yield greater vocal efficiency, making singers better faster. The goal of this series, "Minding the Gap," is to bridge the divide between traditional voice pedagogy with the most current research on the brain. This is a dynamic process, and the hope is that this snapshot in scientific time will encourage singers and teachers to follow some of this work as it continues to evolve. Given the constant output in neuroscience research, paradigm shifts are the norm. To that end, it is important to follow the latest work from the diverse minds in the field. The first installment of "Minding the Gap" will explore the field of vocal learning from both an evolutionary and biological perspective. These concepts set the stage for future reviews on the neuroscience of breath, learning, articulation, phonation, emotion, gesture, and more. Each survey will include integrated voice pedagogy and voice science components so that readers can directly apply concepts to their field of study. The hope is that this series will open the door to new lines of inquiry and curiosity, moving our field into a new era of exploration.] The singing instinct, which men have in common with the birds is, without a doubt, at the root of the vocal art. —David Ffrangcon-Davies, The Singing of the Future (1905) Vocalization has both biological and anthropological roots. Humans speak and sing in order to communicate and socially bond. Each individual gains this ability through listening to acoustic models, forming auditory templates, and consolidating sensory information. This results in an identifiable vocal output, as unique as a [End Page 87] fingerprint. When we analyze the parallel evolution that gives rise to our vocal abilities, we gain insight into the inner workings of our complex instrument. Traditional voice pedagogy focuses on the question of how to sing; however, by analyzing our evolutionary story, we gain a greater understanding of why we sing. Ultimately, the why serves the how, leading to a deeper appreciation for our instrument by all who care for the voice. Much discussion around the evolution of complex human behaviors focuses on our primate cousins. We have inherited a great deal from our simian counterparts; chimpanzees, for example, share 99% of our DNA, they laugh when tickled, create strong social bonds, use hand gestures to communicate, mimic,2 and even demonstrate elements of emotion.3 However, two critical components for higher order vocalizations—a flexible vocal apparatus and a brain that coordinates complex sounds—are noticeably absent or severely compromised in our close relatives. Regarding structural elements of the voice, the vocal limitations of nonhuman primates have been partially attributed to the anatomy and configuration of their vocal tract (i.e., a high position of the larynx and a less flexible tongue). This was described in a seminal 1969 paper by Lieberman et al., who used a computer algorithm to extract the phonetic capability of subjects, and thus serve as a model for other nonhuman primates.4 Their measurements concluded that monkeys do not have a physical capacity for complex speech. Although in recent years scientists proved that there is more variability than initially thought,5 the fact remains that adult humans possess a more flexible vocal tract capable of more diverse vocalizations than our primate cousins. A more critical difference, however, lies in the correlative brain regions for...