Development of the head, pinnae, and acoustical cues to sound location in a precocial species, the guinea pig (Cavia porcellus).

Development of the head, pinnae, and acoustical cues to sound location in a precocial species, the guinea pig (Cavia porcellus).
Hear Res. 2017 Nov 01;:
Authors: Anbuhl KL, Benichoux V, Greene NT, Brown AD, Tollin DJ
Abstract
The morphology of the head and pinna shape the spatial and frequency dependence of sound propagation that give rise to the acoustic cues to sound source location. During early development, the physical dimensions of the head and pinna increase rapidly. Thus, the binaural (interaural time and level differences, ITD and ILD) and monaural (spectral shape) cues are also hypothesized to change rapidly. Complex interactions between the size and shape of the head and pinna limit the accuracy of simple acoustical models (e.g. spherical) and necessitate empirical measurements. Here, we measured the cues to location in the developing guinea pig, a precocial species commonly used for studies of the auditory system. We measured directional transfer functions (DTFs) and the dimensions of the head and pinna in guinea pigs from birth (P0) through adulthood. Dimensions of the head and pinna increased by 87% and 48%, respectively, reaching adult values by ∼8 weeks (P56). The monaural acoustic gain produced by the head and pinna increased with frequency and age, with maximum gains at higher frequencies (>8 kHz) reaching values of 10-21 dB for all ages. The center frequency of monaural spectral notches also decreased with a...

Source: Hearing Research - November 1, 2017 Category: Audiology Authors: Anbuhl KL, Benichoux V, Greene NT, Brown AD, Tollin DJ Tags: Hear Res Source Type: research