The fast measurement of head related impulse responses for all azimuthal directions using the continuous measurement method with a servo-swiveled chair

This paper proposes a method for the fast measurement of head related impulse responses (HRIRs) for all azimuthal directions using the continuous measurement method with a subject sitting on a servo-swiveled chair (SSC). The subject faces all azimuthal directions with a constant angular speed as the SSC rotates and hears corresponding spatial sounds. In our continuous measurement method, we use a maximum length sequence (MLS) as the excitation signal, record binaural signals using tiny microphones placed in the subject’s ear canal around 5 mm from the entrance, and feed them, along with the MLS signal, into a PC so that HRIRs can be extracted for all azimuthal directions and discrete elevations. In this paper, the underlying principles behind the method are described and conditions for successful implementation are examined through numerical simulations. Further, the validity of the proposed method is verified using a physical realization and empirical measurements.