Design and validation on a multiple sound source fast measurement system of near-field head-related transfer functions

Near-field head-related transfer functions (HRTFs) are essential to scientific researches of binaural hearing and practical applications of virtual auditory display. High efficiency, accuracy and repeatability are required in a near-field HRTF measurement. As results, there is no reference that is intent on solving the measuring difficult of near-field HRTF for human subjects. In present work, an efficient near-field HRTF measurement system that is based on computer control is designed and implemented, and a fast calibration method for the system is proposed, so as to firstly solve the measurement of near-field HRTF for human subjects. The efficiency of measurement is enhanced by a comprehensive design on the acoustic, electronic and mechanical parts of the system. And the accuracy and repeatability in measurement are greatly improved by careflflly calibrating the positions of sound source, subject and binaural microphones. This system is suitable for near-field HRTF measurement at various source distances within 1.0 m, for both human subject and artificial head. The time for HRTF measurement at a single sound source distance and full directions is within 20 minutes. The measurement results indicate that the accuracy of the system satisfies the actual demand. The system is applicable to scientific researches and can be used to establish individualized near-field HRTF database for human subject.