Determination of auditory thresholds in the brushtail possum (Trichosurus vulpecula)

The auditory abilities of the brushtail possum (Trichosurus vulpecula) have been measured by cochlear potential readings, but no behavioural determina tions of their auditory abilities have been published. Six experimentally n aive possums were trained to perform a two-response conditional discriminat ion between the presence and absence of an 880-Hz tone (at 80 dB). All six possums readily learned this task. The behavioural threshold for this tone was determined using a modified tracking procedure and found to be similar to that reported using cochlear microphonic potentials. One concern with th e current method was the communal nature of the experimental environment so a further threshold determination in a sound-attenuating chamber was condu cted. No substantial difference was noted between the results obtained in t he two threshold determinations. The success of the current method means th at a full, behavioural audiogram for the brushtail possum, which would comp lement the existing cochlear potential data, is now possible. (C) 2001 Else vier Science Inc. All rights reserved.