The pitch of vibrato tones.

A review of previous experiments on the pitch of vibrato tones and the reasons why a new measurement was needed are given. A method of adjustment was used to find the pitch for tones with center frequencies of 220, 440, 880, and 1500 Hz, with total nominal vibrato widths of 50, 100, and 200 cents, and vibrato rates of 4, 6, and 8 Hz. In one case a complex (square) wave was used as the carrier. The pitch is close to the geometric mean of the two extreme frequencies. Another experiment, using an asymmetrical vibrato waveform, shows an averaging of all frequencies present and not just the extreme frequencies.