The third step in the auralization process is to mix the impulse response file created under step 2 (the acoustical signature of the room at the listener’s location) with the characteristics of human hearing to create the binaural response files that will be used in the auralization.

The characteristics of human hearing have been measured and converted into head-related transfer functions (HRTF) that represent the effects the head, torso, shoulders and ears have on the sound that reaches the listeners ear drums.

The discrete pulses of the impulse response file will be convolved with the right and left ear transfer functions using FFT (Fast Fourier Transform) to produce the binaural signal that will be used to convolve the dry (uncolored reference) audio signal and produce the auralization.