Pure-tone birdsong by resonance filtering of harmonic overtones
| Autor: | Carel ten Cate, Gabriël J. L. Beckers, Roderick A. Suthers |
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| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | Proceedings of the National Academy of Sciences, 100(12), 7372-7376 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Pure-tone song is a common and widespread phenomenon in birds. The mechanistic origin of this type of phonation has been the subject of long-standing discussion. Currently, there are three hypotheses. ( i ) A vibrating valve in the avian vocal organ, the syrinx, generates a multifrequency harmonic source sound, which is filtered to a pure tone by a vocal tract filter (“source-filter” model, analogous to human speech production). ( ii ) Vocal tract resonances couple with a vibrating valve source, suppressing the normal production of harmonic overtones at this source (“soprano” model, analogous to human soprano singing). ( iii ) Pure-tone sound is produced as such by a sound-generating mechanism that is fundamentally different from a vibrating valve. Here we present direct evidence of a source-filter mechanism in the production of pure-tone birdsong. Using tracheal thermistors and air sac pressure cannulae, we recorded sound signals close to the syringeal sound source during spontaneous, pure-tone vocalizations of two species of turtledove. The results show that pure-tone dove vocalizations originate through filtering of a multifrequency harmonic sound source. |
| Databáze: | OpenAIRE |
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