Obstacle perception is a skill to detect presence of "silent" object, such as wall, etc., by perceiving the acoustical cues, such as reflected sound, etc., through auditory sense. This skill is very important for orientation and mobility (O&M) of the blind. We are studying the training system for acquiring this skill in the blind education and rehabilitation by using acoustical technologies. Our training system can reproduce ideal sound fields for learning the principle of obstacle perception. We are also distributing the audio CD that contains these sound fields to the people concerned with the blind education and rehabilitation.