Dichotic listening

Dichotic Listening is a psychological test commonly used to investigate selective attention within the auditory system and is a subtopic of cognitive psychology and neuroscience. Specifically, it is "used as a behavioral test for hemispheric lateralization of speech sound perception." During a standard dichotic listening test, a participant is presented with two different auditory stimuli simultaneously (usually speech). The different stimuli are directed into different ears over headphones. Participants are asked to pay attention to one or both of the stimuli. Later, they are asked about the content of either the message they were asked to attend to or the message that they were not told to listen to.