Detection and discrimination of complex sounds by birds in quite and noise.
R. J. Dooling
The acoustic communication system of birds involves some of the most complex acoustic signals in nature. It is clear from ethological studies that birds perceive much of this complexity but the exact features to which they are sensitive are somewhat elusive.
R. J. Dooling
The acoustic communication system of birds involves some of the most complex acoustic signals in nature. It is clear from ethological studies that birds perceive much of this complexity but the exact features to which they are sensitive are somewhat elusive.
Working with synthesized harmonic complexes having exceptionally short waveform periods, we have shown psychophysically that birds are 2-3 times better than humans, and probably other mammals, in a particular kind of temporal feature of complex sounds – the fine structure. Importantly, the superior avian sensitivity to temporal phase or fine structure extends to the discrimination of bird vocalizations and behavioral results are supported by physiological and anatomical results from the auditory periphery.
Masking studies using these same harmonic complexes are beginning to reveal some of differences in the way that the auditory periphery of mammals and birds process complex acoustic waveforms. One interesting emerging aspect of this work is the species differences in how well birds can detect and discriminate complex sounds bird vocalizations against a background of noise. Generally, birds require a higher signal-to-noise ratio to discriminate between two vocalizations than to detect a vocalization. These findings have relevance for understanding the effects of anthropogenic noise on avian acoustic communication in natural environments.
