Head related transfer function measurement in reverberant rooms

Head related transfer functions (HRTF) and their corresponding time domain impulse responses have a decisive role into sound localization for humans and, an individualized measured set can improve the localization accuracy and overall quality of a virtual sound placement system. The measurement proves to be difficult in absence of an anechoic chamber and the use of available measured HRTF might not be sufficient for custom setups. This paper describes a fast measurement system for head related impulse responses and the corresponding processing for extracting the HRTF for a listener in normal reverberant rooms. The impulse responses are measured using the exponential sine sweep method as the listener rotates relative to a sound source. The influence of the loudspeaker is measured separately and compensated with a Wiener filter. To simulate the anechoic conditions the head related impulse response is selected only from the direct soundwave part of the measured room impulse response provided that the experimental setup is calibrated appropriately.