The Fish Barn

Otoacoustic Interrelationships of the Barn Owl

Significant debate still exists about the biophysical mechanisms at work in otoacoustic emission (OAE) generation and how such may differ between mammals and non-mammals given gross morphological differences (e.g., existence of basilar membrane traveling waves, degree of tectorial membrane coupling). To further elucidate general principles at work, we examined the barn owl for interrelationship...

Barn owl and sound localization

The barn owl is a nocturnal predator with excellent sound localization ability. Due to the asymmetric ears of this bird, the interaural time and level differences, respectively, provide information for the horizontal and vertical direction of a sound source. Forty years of behavioral, anatomical and physiological research on the owl’s auditory system have revealed that these two acoustic cues a...

Vernier acuity in barn owls

Vernier acuity thresholds were obtained psychophysically in three adult barn owls with vertical bars and sinusoidal gratings. A minimal displacement threshold of 0.58 arcmin was observed with the bar stimulus under binocular viewing conditions. The mean binocular bar threshold was 2.51 arcmin. Bar thresholds were lower than grating thresholds. Monocular thresholds, obtained in one bird only, we...

The Computation of Sound Source Elevation in the Barn Owl

The midbrain of the barn owl contains a map-like representation of sound source direction which is used to precisely orient the head toward targets of interest. Elevation is computed from the interaural difference in sound level. We present models and computer simulations of two stages of level difference processing which qualitatively agree with known anatomy and physiology, and make several s...

Temporal coding in the auditory brainstem of the barn owl