When birds and humans sing it sounds completely different, but now new research reported in the journalNature Communications shows that the very same physical mechanisms are at play when a bird sings and a human speaks.
Birds and humans look different, sound different and evolved completely different organs for voice production. But now new research published in Nature Communications reveals that humans and birds use the exact same physical mechanism to make their vocal cords move and thus produce sound.
“Science has known for over 60 years that this mechanism – called the myoelastic-aerodynamic theory, or in short the MEAD mechanism- drives speech and singing in humans. We have now shown that birds use the exact same mechanism to make vocalizations. MEAD might even turn out to be a widespread mechanism in all land-dwelling vertebrates”, says lead author of the paper, Associate Professor Dr. Coen Elemans, Department of Biology, University of Southern Denmark. Co-authors of the paper are from Emory University, Max Planck Institute for Ornithology and Palacky University.
Over the last year Dr. Elemans and his colleagues studied six different species of bird from five avian groups. The smallest species, the zebra finch, weighs just 15 grams, and the largest one, the ostrich, weighs in at 200 kg. All studied birds were revealed to use the MEAD mechanism, just as humans do.
In the human voice box, or larynx, air from the lungs is pushed past the vocal cords, which then start moving back and forth sideways like a flag fluttering in the wind. With each oscillation the larynx closes and opens, making the airflow stop and start, which creates sound pulses. “Such vocal fold oscillations occur from about 100 times/sec in normal speech to one of the highest possible notes sung in opera at about 1400 times/sec, a F6 in Mozart’s “Die Zauberflöte”, adds voice expert and co-author Dr. Jan Švec of Palacky University in the Czech Republic.
To be Continued on