Official Definition:
“Auditory imagery is a form of mental imagery that is used to organize and analyze sounds when there is no external auditory stimulus present.”
Godøy, Rolf Inge & Jørgensen, Harald (2001). Musical Imagery. Swets & Zeitlinger, Lisse (Holland). ISBN 90-265-1831-5.
Informal definition:
Auditory imagery in literature is to use the description of words to make the sound of the description appear in the reader's mind.
Example: As she walked through the wintery woods, her teeth chattered and the leaves crunched under her feet.
Etymology:
Borrowed from Latin audītōrius (“ pertaining to a hearer or hearing ”), from audiō (“ to hear ”) + -tōrius (“-tory ”, adjectival suffix). Adjective . auditory (not comparable) Of, or relating to hearing, or to the sense or organs of hearing.
“auditory”, in Lexico, Dictionary.com; Oxford University Press, 2019–present. “auditory”, in Merriam–Webster Online Dictionary.