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)