by means of physical waves, rays and particles of the physical universe, impressions of the environment enter through the "sense channels" such as the eyes and optic nerves, the nose and olfactory (of the sense of smell) nerves; the ears and aural (of the sense of hearing) nerves; interbody nerves for interbody perceptions, etc., etc. These are all perceptions up to the instant they record as facsimiles at which moment they become recordings. When recalled they are perceptions again, being again entered into sense channels from the recall side. There are over half a hundred separate perceptions all being recorded at once. —APA Glossary (app 11.7.90)