Altered auditory feedback with a biophysical model for sound production

A. AMADOR; J. D. SITT.; E. ARNEODO; F. GOLLER; G. B. MINDLIN

Chicago, USA

Simposio; The Tucker-Davis symposium on advances and perspectives in auditory neurophysiology.; 2009

Songbirds have been widely studied as animal models for exploring sensorimotor plasticity in a well de-fined neural circuit critical for learning and memory. The parallels to human vocal development andsound production mechanisms are remarkable. Male zebra finches (Taeniopygia guttata) learn songduring development, resulting in a stereotyped adult song that, in normal conditions, does not subse-quently change. Altered auditory feedback experiments have shown that song learning and adult main-tenance is an active process, but little is known about the mechanisms of auditory feedback evaluation.In the last years, a number of mathematical models have been proposed in order to integrate a largebody of experimental work with the expected mechanical processes involved in birdsong production.However, the mechanisms of how the avian sound source might contribute to spectral richness are lar-gely unknown. In order to address this question, we analyse the zebra finch song, that presents sylla-bles with low fundamental frequencies that are spectrally rich, and syllables with high fundamentalfrequency that are nearly tonal. In this work we present the study of a nonlinearly enhanced flappingmodel for birdsong production. The characteristics found in the zebra finch song can be synthesizedusing as input for the model physiological measurements recorded while the bird is singing. Using thismodel we can generate realistic synthetic song while the bird is singing. In this way, altered auditoryfeedback experiments can be performed as the acoustic properties of the synthetic song are contro-lled by parameters in the model.