diplacusis

noun
dip·​la·​cu·​sis | \ ˌdip-lə-ˈkyü-səs How to pronounce diplacusis (audio) \
plural diplacuses\ -​ˌsēz How to pronounce diplacuses (audio) \

Medical Definition of diplacusis

: the hearing of a single tone as if it were two tones of different pitch