This implies that virtual pitch can be perceived although neither of the two ear signals includes any periodicity that would correspond to the pitch perceived. This implies that there does not exist any periodicity in the ear signal that would correspond to the pitch perceived. It is hard to see how a time-domain model should be able to account for the phenomena of pitch shifts and octave stretch . By contrast, the structure of a sound signal is heavily dependent on both linear distortion and superimposed additional sound. By contrast, the structure of any time signal is heavily dependent on component phases.
Pitch is multiple , and multiple sound objects can elicit pertinent pitches.
Rather, pitch determination and sound-object segregation must go hand in hand. In spite of these difficulties with explaining virtual pitch in the time domain, a considerable number of attempts of that type have been described in the literature until present days. However, I am not aware of a satisfactory solution. Returning to the notion that two separate solutions are required for the explanation of spectral pitch and virtual pitch, respectively, up to this point the question remained open as to how separate are these two mechanisms. This indeed is how the virtual-pitch theory works.