60 Frank Kodman, Jr., Ph.D. 



amounts to a single axis of perception and therefore are unable to 

 experience sound inversion. 



In summary, our explanation seems to account for the perception 

 of an inverted visual object in space but only rotation and not inversion 

 of an auditory sound. Rotation is but a form of sound localization. We 

 can readily alter the temporal order of a tonal sequence and still lack 

 true inversion of the auditory sound. The explanation presented here 

 places its primary emphasis on the energy which reaches the receptor. 

 The interested reader may find our explanation challenging and per- 

 haps even inadequate. However, the fundamental observation that 

 we do not perceive "upside-down" sound seems to be an original one 

 worthy of inquiry. 



Acknowledgements 



The writer is indebted to Walter Whippo and Richard Griffith for 

 several pertinent suggestions. 



