Question

How would horizontal sound localization differ between a mouse and an elephant?

Answer 1

Localization sounding the horizontal dimensions that is by judging whether the sound is to our left or right involves detecting interaural time and level differences. That's why we judge a sound to be in the right hemifield because it reaches the right ear earlier than left year.

In mouse sounding dimensionswere measured using prepulse inhibition of the acoustic startle reflex as the indicator response for stimulus detection. Small mammals like mice can be expected to have difficulty in localizing sound source since the interaural time differences are small and interaural phase differences may be processed only up to about 5kHz where phase coding in the auditory nerves rapidly decreases. So that phase is not helpful for localizing in the high frequency range into which mouse hearing extends. And also interaural intensity differences are non existent or small in the low frequency range.

An young elephant was determine its absolute sensitivity, frequency,discrimination thresholds and sound localization thresholds. The elephant was found to have anauidibility curve similar to that of other mammal but one that is more sensitive to low frequencies than any other mammalian audigram including human's. The elephant sensitivity to frequency differences at low frequencies was found to equal that of human's. Finally the elephant was found to be very accurate at localizing sounds. The elephant ability to localize pure tones suggested that it could use both binaural time and intensity differences to localize sounds.