Alonso Rodrigo, Goller Franz, Mindlin Gabriel B
Department of Physics, FCEyN, University of Buenos Aires, Ciudad Universitaria, Pab I, cp 1428, Buenos Aires, Argentina.
Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Mar;89(3):032706. doi: 10.1103/PhysRevE.89.032706. Epub 2014 Mar 10.
Frequency modulation is a salient acoustic feature of birdsong. Its control is usually attributed to the activity of syringeal muscles, which affect the tension of the labia responsible for sound production. We use experimental and theoretical tools to test the hypothesis that for birds producing tonal sounds such as domestic canaries (Serinus canaria), frequency modulation is determined by both the syringeal tension and the air sac pressure. For different models, we describe the structure of the isofrequency curves, which are sets of parameters leading to sounds presenting the same fundamental frequencies. We show how their shapes determine the relative roles of syringeal tension and air sac pressure in frequency modulation. Finally, we report experiments that allow us to unveil the features of the isofrequency curves.
频率调制是鸟鸣的一个显著声学特征。其控制通常归因于鸣管肌肉的活动，这些肌肉会影响负责发声的唇的张力。我们使用实验和理论工具来检验这样一个假设：对于像家雀（Serinus canaria）这样发出音调声音的鸟类，频率调制由鸣管张力和气囊压力共同决定。对于不同模型，我们描述了等频率曲线的结构，等频率曲线是导致声音呈现相同基频的参数集。我们展示了它们的形状如何决定鸣管张力和气囊压力在频率调制中的相对作用。最后，我们报告了一些实验，这些实验使我们能够揭示等频率曲线的特征。
