1
general::
Adjust a receiver so as not to receive a signal, as in Let's tune out all this interference. [Early 1900s] 1. Dissociate oneself from one's surroundings; also, disregard, ignore. For example, The average reader, used to seeing lots of color images, tunes out when confronted with big blocks of text, or Some mothers are expert at tuning out the children's whining and quarreling. [1920s] For an antonym, see TUNE IN. 2.
American Heritage Idioms
2
general::
Phrase(s): tune out
Fig. to cease paying attention to anything at all. • I wasn’t interested, so I just tuned out. • I think that most of the audience tuned out during the last part of the lecture., Phrase(s): tune someone or something out
to put someone or something out of one’s consciousness; to cease paying attention to someone or something. • I had to tune the radio out in order to concentrate. • I tuned out what the speaker was saying and daydreamed for a while.
McGrawhill's American Idioms And Phrasal Verbs