IDENTIFICATION OF CONCURRENT HARMONIC AND ANHARMONIC VOWELS

It is known that the auditory system uses harmonicity cues to separate concurrent voiced sounds that differ in fundamental frequency (FO). W hat is less clear is whether the harmonicity of the target sound is us ed to enhance it within the mixture, or whether that of the background is used to cancel it and thus allow the target to emerge. An experime nt was designed to answer this question. Subjects were presented with pairs of concurrent synthetic vowels, each of which was either harmoni c or inharmonic. Results were scored according to the harmonicity of t he vowel identified (the target), and that of the second vowel (the gr ound). For a given target, identification was best for harmonic ground s, except when target and ground were both harmonic and had the same F O. This is compatible with the cancellation hypothesis. On the other h and, identification for a given ground was worse when the target was h armonic. This is the opposite of the effect predicted by the enhanceme nt hypothesis.