Fig. 3. Gating of sound in the amplitude-modulated part of e2, recorded in trachea (A) and interclavicular air sac pressure (ICAS) (B). Recordings A and B are from different coos but originate from the same individual. Both sound oscillograms in the trachea and ICAS show that phonation is completely interrupted by silent intervals of 10 ms. This modulation pattern corresponds to the pattern of flow rate in the trachea, which is reduced to zero or near-zero during silent intervals. ICAS pressure gradually increases in the first half of the amplitude-modulated part, although in some recordings, like in this example, the rate of increase is reduced during the sound pulses. Cranial thoracic air sac (CTAS) pressure patterns are similar to those in the ICAS in this part of the coo and are therefore not shown.

Return to article