A pair of impulse responses from either two matched microphones measured simultaneously, or from a single microphone measured in two locations. This option is used for calculation of binaural parameters, see the Interaural crosscorrelation section. The microphones are normally placed in or at the ear canal of a dummy head or a real person. The lower impulse response (in the figure below named Position2) will only be used for these parameters, other parameters are calculated from the upper impulse response.