Habitat acoustics and primate communication.

The acoustic characteristics of three tropical habitats were investigated to determine how they might constrain the structure of primate signals. Ambient noise was measured, along with signal attenuation and aspects of signal degradation (reverberation, amplitude fluctuations, and pulse train modulation depth). These measures allowed estimation of the effects of habitat acoustics on the distances over which calls would be audible (the "active space") and over which primates could reliably transmit amplitude-modulated or pulse-coded information.