Descriptive analyses of orangutan faux-speech; a) Time series of an orangutan faux-speech bout.

<p>Dark blue line indicates raw power spectra (dB), light blue line indicates acoustic amplitude envelop measure, and red line indicates inter-lip distance measure. <b>b)</b> Spectrographic representation of faux speech. Red dots indicate formats and blue line indicates fundamental frequency measure. <b>c)</b> Average estimates of raw power spectra; <b>d)</b> Detrended power spectra; <b>e)</b> Coherence of orangutan faux-speech.</p>