Effect of sound level on virtual and free-field localization of brief sounds in the anterior median plane.

Effect of sound level on virtual and free-field localization of brief sounds in the anterior median plane.
Hear Res. 2018 Jun 14;365:28-35
Authors: Marmel F, Marrufo-Pérez MI, Heeren J, Ewert S, Lopez-Poveda EA
Abstract
The detection of high-frequency spectral notches has been shown to be worse at 70-80 dB sound pressure level (SPL) than at higher levels up to 100 dB SPL. The performance improvement at levels higher than 70-80 dB SPL has been related to an 'ideal observer' comparison of population auditory nerve spike trains to stimuli with and without high-frequency spectral notches. Insofar as vertical localization partly relies on information provided by pinna-based high-frequency spectral notches, we hypothesized that localization would be worse at 70-80 dB SPL than at higher levels. Results from a first experiment using a virtual localization set-up and non-individualized head-related transfer functions (HRTFs) were consistent with this hypothesis, but a second experiment using a free-field set-up showed that vertical localization deteriorates monotonically with increasing level up to 100 dB SPL. These results suggest that listeners use different cues when localizing sound sources in virtual and free-field conditions. In addition, they confirm that the worsening in vertical localization with increasing level continues beyond 70-80 dB SPL, the highest levels tested by previous studies. Further, they suggest that vert...

Source: Hearing Research - June 14, 2018 Category: Audiology Authors: Marmel F, Marrufo-Pérez MI, Heeren J, Ewert S, Lopez-Poveda EA Tags: Hear Res Source Type: research