Speakers are no different from microphones in the technical words because speakers can turn to microphone.
in whonix docs slightly covering that through turning speakers into microphone study https://www.whonix.org/wiki/Microphone#Eavesdropping_Risk)
Cross Device Tracking
DolphinAttack: Inaudible Voice Commands
MOSQUITO:Covert Ultrasonic Transmissions between Two Air-Gapped Computers using Speaker-to-Speaker Communication
Explanation video by The Hated One: