Figure 3.

Standard coo. (a) Spectrogram and oscillogram of dove coo. Superimposed on the spectrograms is a fundamental frequency analysis (colour represents sound amplitude). (b) Bronchial pressure. The vertical dotted line indicates the transition from expiration to inspiration. (c) Rectified EMG of tracheolateralis muscle (TL) and TL activity associated with sound elements (red areas). (d) Stress generated by TL, (e) transmural stress (bottom trace) and sum of transmural and TL stress. p_t, transmural pressure; p_TL, stress generated by TL; p_sum, sum of p_t and p_TL.