Abstract
Various sounds effects, included infra- and hypersonic effects on living bodies have been the subject of many discussions. In this report, EEGs were measured and those effects were evaluated using a headphone with special technology, i.e. ultra sound technology (UST), an audio-player with a fluency method and an audio CD specially prepared for improvement of auditory perception. ERPs (event related potentials of the brain) were studied before and after listening to the special CD. The α wave ratios on the frontal to the oc-cipital area tended to become large when the sounds included a high frequency band. Latencies of P300 of ERPs tended to become short after listening to the special CD. Amplitudes of MMN (mismatch negativity), that is small potential changes caused by the preconscious perception of slight differences of sounds, be-came small after listening to the special CD.
