Critical Band for Frequency: a Revision of the Limits.

Numerous music acoustics and psychomusicology text books claim that it is not possible to hear the individual pitches when two simultaneous tones are separated by a half-step. Musicians, on the other hand, find that their day-to-day experience does not correspond well with this claim. Remarkably little research literature was found which tests this question in a musical situation. Because this task pits the information available in the frequency domain and that available in the time domain in opposition, it is important to determine who is right. The results of a test in which subjects used the method of adjustment to match a tone to either of two, simultaneous tones are presented. These subjects qualified to take the test by demonstrating fine-tune pitch matching ability to a single tone. In contrast to the previously accepted limit of frequency discrimination, the results indicate that the subjects were able to effectively analyze one of the pitches out of a two-tone stimulus whose frequencies were as little as one-quarter step apart.