Calibration of Room Impulse Response Measurement Chain with Free-field Simulated Models
* Presenting author
Auralization techniques are used in many applications within the acoustics context. This powerful tool allows recreating sound stimulus via convolution of an anechoic recording (of the desired sound signal) with the binaural room impulse response (BRIR) of a specific environment. Nevertheless, the frequency response (FRF) of the instrumentation employed in the BRIR's (or RIR) evaluation may generate a negative impact (coloration) in the auralization results. In this context, this work purposes a method to extract the free-field response of the measurement chain. The technique consists of finding the direct sound, the first reflection inside the RIR and designing a hybrid window (with smooth decay) to avoid spectrum leakages. To test effectiveness, five distinct sound sources were used to obtain the BRIRs of an auditorium/lecture room at the Federal University of Santa Maria, Brazil. The frequency coloration caused by the instrumentation can be correct with an appropriate inverse filtering process (extracted from the instrumentation free-field response) to properly convolve the anechoic recordings. Thus, the BRIRs would not contain the FRFs of the instruments. Ultimately, the following step is the comparison concerning corrected and uncorrected outcomes.