Development of a measurement system for obtaining head relative transfer function of a head and torso simulator

The human being, because of his complex audition system, has the ability to identify the spatial position of any sound from the surrounding environment. The objective of this work is to develop a measurement system that enables to mathematically model the hearing system by using a set of transfer functions. These equations, called head related transfer function (HRTF), synthesize mathematically the binaural transformation that the listener produces (principally from the torso, the head, and the pinna) in the audition process. To find the HRTF, the measurement system uses an acoustic dummy called head and torso simulator. With two microphones located in their ears, this dummy captures the sound with the same binaural properties as a real listener. The mathematical process to obtain these transfer functions is based on the LTI systems theory, using as excitation signal the sine sweep. Matlab was chosen for the processing environment, taking advantage of its flexibility on the digital sign process and their powerful computational tools.