Free-field perceptual evaluation of virtual acoustic rendering algorithms using two head-related impulse response delay treatment strategies

Sound scenes can be auralized over headphones using binaural rendering techniques in conjunction with a set of head-related impulse responses (HRIRs). If the directions of the sound objects to be rendered are known, either virtual loudspeaker or Ambisonic scene-based techniques may be used, each of which introduce spatial and timbral artifacts at lower spatial resolutions. Neal and Zahorik quantitatively evaluated the effect of separately applying the HRIR delays to time-aligned HRIRs for use with virtual loudspeaker array techniques, referred to as the prior HRIR delays treatment strategy (J. Acoust. Soc. Am. 2022). The present work aims to perceptually validate their quantitative results in a listening study. Free-field point sources were binaurally rendered using five different methods: vector-based amplitude panning, Ambisonics panning, direct spherical harmonic transform of the HRIR set, MagLS, and Principal Component-Base Amplitude Panning (Neal and Zahorik, Audio Eng. Soc. AVAR Conference 2022). Renderings were simulated at various directions and spatial resolutions, both with and without the prior HRIR delays treatment strategy and compared to direct HRIR convolution. Broadband noise served as a critical test signal for revealing changes in timbre and localization and a high-resolution binaural head HRIR dataset was used. The subjective data analysis will be presented.