Judged similarity in pitch of octave multiples

Subjects with musical training, who could identify musical intervals within octaves, were tested on their ability to identify musical intervals when the higher note was at several different octave multiples. Some subjects (but not all) showed very high scores on such cross-octave interval recognition tests. Two other groups of subjects were tested on ability to recognize pitch similarities for octave multiples. Only a few subjects showed evidence of perceiving pitch similarities. Our results do not support the hypothesis thatall subjects perceive a common pitchchroma at octave multiples.