An Eeg-Based Study of Auditory Sensitivity in Spatial Hearing

Spatial hearing is the psychological basis of human sound localization and plays an important role in human daily life. Previous studies have mostly used behavioral methods to measure human ear’s abilities to discriminate spatial sound source location, while the encoding mode of source location information in auditory cortex and the form of sensitivity representation remain unclear. In this study, mismatch negativity (MMN) was used as an indicator of spatial auditory sensitivity, and the oddball paradigm was used to measure the electroencephalograph (EEG)-based auditory responses caused by different spatial sound sources. Two stimulus conditions (SCs), corresponding to the front and right acoustic fields, were considered, and three different deviation magnitudes were set under each SC. Experimental results showed that a larger deviation magnitude led to a larger MMN response, and the MMN latency increased with the increase of sound source lateralization. In addition, the threshold of human ear to different spatial azimuth sound sources could reach 5°. The present work indicated that MMN could serve as a potential neurophysiological index accounting for the ability of sound source localization.