1. Audio medium for educational use, having plural channels from which prerecorded sounds may be reproduced, comprising a multiplicity of sets or prerecorded sounds on said medium, each said set having a dichotic presentation and a diotic presentation, each said dichotic presentation having a stimulus on one of said channels and a first response, corresponding to said stimulus, on a second of said channels, and each said diotic presentation having a second response on both said one and said second channels, said second response of each said set corresponding to the said stimulus of that set.
1. Audio medium for educational use, having plural channels from which prerecorded sounds may be reproduced, comprising a multiplicity of sets or prerecorded sounds on said medium, each said set having a dichotic presentation and a diotic presentation, each said dichotic presentation having a stimulus on one of said channels and a first response, corresponding to said stimulus, on a second of said channels, and each said diotic presentation having a second response on both said one and said second channels, said second response of each said set corresponding to the said stimulus of that set. 2. Audio medium as in claim 1, wherein said second response is a reproduction of said first response.