An auditory brain-computer interface using virtual sound field

Brain-computer interfaces (BCIs) exploring the auditory communication channel might be preferable for amyotrophic lateral sclerosis (ALS) patients with poor sight or with the visual system being occupied for other uses. Spatial attention was proven to be able to modulate the event-related potentials (ERPs); yet up to now, there is no auditory BCI based on virtual sound field. In this study, auditory spatial attention was introduced by using stimuli in a virtual sound field. Subjects attended selectively to the virtual location of the target sound and discriminated its relevant properties. The concurrently recorded ERP components and the users´ performance were compared with those of the paradigm where all sounds were presented in the frontal direction. The early ERP components (100-250ms) and the simulated online accuracies indicated that spatial attention indeed added effective discriminative information for BCI classification. The proposed auditory paradigm using virtual sound field may lead to a high-performance and portable BCI system.