Universal mechanisms of sound production and control in birds and mammals

• Authors: C.P.H. Elemans, University of Southern Denmark; J.H. Rasmussen, University of Southern Denmark; C.T. Herbst, Palacky University; D.N. Düring, University of Southern Denmark; S.A. Zollinger, Max Planck Institute for Ornithology; H. Brumm, Max Planck Institute for Ornithology; K. Srivastava, Emory University; N. Svane, University of Southern Denmark; M. Ding, University of Southern Denmark; O.N. Larsen, University of Southern Denmark; Samuel Sober, Emory University; J.G. Švec, Palacky University
• Journal Title: Nature Communications
• Volume: Volume 6
• Publisher: Nature Publishing Group: Nature Communications | 2015-11-27, Pages 8978-8978
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1038/ncomms9978
• Subjects: Biology, Zoology; Biology, General
• Keywords: Biological sciences; Zoology

Abstract

As animals vocalize, their vocal organ transforms motor commands into vocalizations for social communication. In birds, the physical mechanisms by which vocalizations are produced and controlled remain unresolved because of the extreme difficulty in obtaining in vivo measurements. Here, we introduce an ex vivo preparation of the avian vocal organ that allows simultaneous high-speed imaging, muscle stimulation and kinematic and acoustic analyses to reveal the mechanisms of vocal production in birds across a wide range of taxa. Remarkably, we show that all species tested employ the myoelastic-aerodynamic (MEAD) mechanism, the same mechanism used to produce human speech. Furthermore, we show substantial redundancy in the control of key vocal parameters ex vivo, suggesting that in vivo vocalizations may also not be specified by unique motor commands. We propose that such motor redundancy can aid vocal learning and is common to MEAD sound production across birds and mammals, including humans.