A pretty fun drawing, in addition to the excellent spelling of whispering and cabinet, done on the back of an advertisement for a shredded wheat sponsored drawing content, with a deadline of December 31, 1929 (one guesses issued well before the Stock Market crash.) Though I haven't been able to find a specific reference for the "Colorphonic True Atmophonic" phonographic cabinet, and can't quite make out the name of the maker drawn on the underside of of the cabinet's lid, it looks like a pretty fancy one of the earlyish 20th century variety, which its maker captured pretty charmingly I'd say! 

7 3/8" x 3 3/8" and in good condition, with minor bumps/flagging to the bottom corners.