Magnetoencephalography (MEG) is one of the most important non-invasive measurements of human brain activity and a valuable technology to understand human sense, cognition, and various actions in daily life. Using the advantage of MEG; the excellent time resolution and good signal source localization, we found the olfactory nervous center in the orbito-frontal area and a fine control mechanism on attention and emotion. Ultrasonic hearing has been recently revealed by bone conduction method with an ultrasound vibrator using MEG, so that the development of a ultrasonic hearing aid is expected for hearing deaf people.