Project: Research project

Project Details


Sound localization is a critically important part of sound detection for
all vertebrates. Since vertebrates live in many different habitats,
various species may use different cues to localize sound sources.
Comparative auditory research will help establish a general biological
context within which the hearing of all vertebrates, including humans, can
be better understood. Sound localization usually refers to the processes
of determination of the position of a sound source and is closely related
to two fundamental questions: where does the sound come? and how far is
the sound source? The proposed project will focus on the first question.

This project is directed at understanding the ability and mechanisms of
sound localization by a non-mammalian vertebrate, the fish Astronotus
ocellatus. Directional hearing in fish has been studied since von Frisch
and Dijkgraaf (1935). Previous behavioral, anatomical, and
neurophysiological studies have demonstrated the ability of directional
hearing in a few fish species and have give some ideas about possible
mechanisms underlying sound localization. However, these data are very
limited and are mainly obtained from two fish species: cod (Gadus morhua)
and goldfish (Carassius auratus). The overall ability of directional
hearing has not been systematically studied in any fish species, and what
cues fish use to localize sound sources are still unclear. The proposed
work will investigate directional hearing in Astronotus ocellatus using a
cardiac conditioning method. The focus is on the following specific
questions: 1) What is the directional sensitivity of fish in the
horizontal, sagittal, and frontal planes? 2) What is the smallest angle
that fish are able to distinguish between two spatially separated sound
sources? 3) Are fish able to use the cue of phase difference between
sound pressure and particle motion to discriminate sound sources from
opposing directions?
Effective start/end date8/1/957/31/98


  • National Institute on Deafness and other Communication Disorders
  • National Institute on Deafness and other Communication Disorders


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