Figure 3. Left syringeal devocalization abolishes the majority of the Bengalese finch song.

A) The intact song of a Bengalese finch is displayed in the top of the figure. The introductory notes are lower frequency notes, followed by a series of higher frequency song syllables. B) The introductory notes remained intact following left devocalization, but the remainder of the song syllables were no longer produced. The shaded box illustrates the presence of broadband noise “clicks” that appeared to coincide with the onset of the higher frequency song syllables. These “clicks” were repeatedly produced after the introductory notes, suggesting the syllable onsets of higher frequency syllables were produced by the right sound source, but the higher frequency notes were not produced without the left sound source.