Quantifying active brain areas at spatial hearing process using Electroencephalography (EEG) source localization approach

¹ Doctoral Program Engineering Physics, Faculty of Industrial Technology (FTI), Institut Teknologi Bandung, Bandung 40132, Indonesia
² Instrumentation and Control Research Group, Faculty of Industrial Technology (FTI), Institut Teknologi Bandung, Bandung 40132, Indonesia

^* Corresponding author: supri@tf.itb.ac.id

Abstract

The human ability for spatial hearing encourages the development of spatial audio technology to support many human activities. Spatial audio mimics the real-life sound and provides a more immersive hearing experience as if the listener were present in the environment where the sound source was recorded. Recently, research on how spatial hearing processes are encoded in the brain has begun to be developed. As a modality for brain activity measurement that is non-invasive and has a high temporal resolution, Electroencephalography (EEG) is suitable for studying brain responses to moving sound stimuli. This study compared brain activity in hearing stereo and spatial audio stimulus. Through measurements using 21 EEG electrodes on the scalp, the results showed an increase in the mean PSD for all Theta, Alpha, and Beta waves in the spatial audio stimulus compared to stereo audio. The most significant increase in the mean PSD occurred in the Beta wave of 93.8008 µV2/Hz. Furthermore, the source localization approach with Independent Component Analysis (ICA) and Low-resolution Brain Electromagnetic Tomography (LORETA) method was used to estimate and quantify the active brain area of this process. The results showed an activation of the non-auditory cortex when the subject was hearing spatial audio stimulus. By using Paired T-Test of current density for both hearing processes, the results showed there was no significant difference (p > 0.05) in Brodmann area (BA) 41 (Primary Auditory Cortex) and BA 42 (Secondary Auditory Cortex). Meanwhile, for the spatial audio hearing process, there was a significant difference (p < 0.05) in BA 6 (Premotor Cortex), which is related to spatial orientation, and BA 9 (Dorsolateral Prefrontal Cortex), which is associated with executive functions, including working memory and selective attention. This study offers potential insights into spatial hearing research and immersive audio production.