Near-field head-related transfer functions of a artificial head and its characteristics

A spherical dodecahedron sound source and its spatial orientation system are used to measure and establish the near-field head related transfer function(HRTF) database of a KEMAR artificial head.Base on the database,the variations of near-field HRTFs in frequency domain and time domain with the sound source distance are analyzed.The distance localization cues included in near-field interaural level difference(ILD) and interaural time difference(ITD) resulted from near-field HRTFs are evaluated.The results indicate that the measurement system and data are accurate and repeatable,and the distance localization cues at low frequency below 1 kHz are reserved in the measured data. Moreover,the magnitude responses of near-field HRTFs as well as ILD vary obviously with source distance;while the ITD below 2 kHz calculated by cross-correlation slightly vary with the source distance.The present database and analysis provide basis for the applications of sound source distance localization.