An auditory approach to understanding the effects of noise on communication in natural environments

Abstract

Animals, like humans, frequently communicate using long-range acoustic signals in networks of several individuals. In socially and acoustically complex environments, however, communication is characterized by a variety of perceptual challenges that animals strive to overcome in order to interact successfully with conspecifics. Species differences in auditory sensitivity and the characteristics of the environment are major factors in predicting whether environmental noise limits communication between animals or interferes with detection of other biologically important sounds. Working with both birds and humans and using both synthetic and natural noises in both laboratory and field tests, we have developed a model for predicting the effects of particular masking noises on animal communication. Moreover, by comparing birds listening to bird vocalizations in noise with humans listening to speech in noise, we gain a novel intuitive feel for the challenges facing animals in noisy environments. This approach of considering communication from the standpoint of the receiver provides a better approach for understanding the effects of anthropogenic noises that exceed ambient levels. For instance, in determining risk to a particular species, effective communication distances derived from this model might be compared to other aspects of the species biology such as territory size.