Neuroacoustics: Study on the Perception of Stereo Reverberant Sound Field at Cortical Level. Issue 4 (December 2013) - Bidondo, Alejandro
On the basis of the Ando's brain hemispheric specialization auditory model, spatial information is processed in the right hemisphere. When hearing a complex sound stimuli, like a monaural sound source reproduced in a reverberant sound field, several independent acoustic cues are processed in both hemispheres simultaneously. To study the brain specialization perceiving these types of sounds, it was developed the Auditory Evoked Potentials analysis for 2000 ms after the first 80 ms from the sound onset, even though the first 300 ms is normally analyzed, and Cortical Activity descriptors, which were applied to Mismatch Negativity electro-physiological signals taken from Left and Right hemispheres. It was possible to measure the specialization of hemispheres by using two different monaural and anechoic sound sources, one with a minimum effective duration of its autocorrelation function (tau e) as low as 0.2 ms and another with minimum tau e of 190ms, both embedded into the same reverberant sound field and reproduced thru headphones. This study opens the possibility to measure the perception of listener envelopment to further develop a subjective descriptor.