Spectral manipulation improves elevation perception with non-individualized head-related transfer functions

Spatially rendering sounds using head-related transfer functions (HRTFs) is an important part of creating immersive audio experiences for virtual reality applications. However, elevation perception remains challenging when generic, non-personalized HRTFs are used. This study investigated whether digital audio effects applied to a generic set of HRTFs could improve sound localization in the vertical plane. Several of the tested effects significantly improved elevation judgment, and trial-by-trial variability in spectral energy between 2 and 10 kHz correlated strongly with perceived elevation. Digital audio effects may therefore be a promising strategy to improve elevation perception where personalized HRTFs are not available.