Investigating head-related transfer function smoothing using a sagittal-plane localization model

A new head-related transfer function (HRTF) smoothing algorithm is presented. HRTF magnitude responses are expressed on an equivalent rectangular bandwidth frequency scale and smoothing is increased by progressively discarding the higher frequency Fourier coefficients. A sagittal plane localization model was used to assess the degree of spectral smoothing that can be applied without significant increase in localization error. The results of the localization model simulation were compared with results from a previous perceptual investigation using an algorithm that discards coefficients on a linear frequency scale. Our findings suggest that using a perceptually motivated frequency scale yields similar localization performance using fewer than half the number of coefficients.