Pitch perturbation detection

Pitch perturbations are defined as normally minute variations in the lengths of adjacent pitch periods of voiced speech. It has been shown that perturbations increase in size and number in the presence of laryngeal abnormalities such as cancerous growths. Previous studies have been limited by the unavailability of electronic equipment of sufficient accuracy to perform the pitch measurements in real time. The apparatus to be described represents an intermediate step in the design of a real-time perturbation detector. Operating in an expanded time scale and using regenerated pulse trains derived from visual measurement of voiced waveforms, perturbation measurements are made which are comparable with the computer-calculated values.