Scaling the perceived width of vibrato tones

Abstract

We have investigated the psychological magnitude of the width of vibrato tones. In the experiments reported here, the signal was a modulated 440-Hz sine wave. The method of magnitude estimation was used with 14 subjects, who heard the vibrato tones produced by a speaker in a room, resulting in a power-law exponent of 0.80. Then eight subjects using the method of magnitude production and listening with headphones set widths for both “twice as wide” and “ half as wide,” yielding an exponent of 1.85. The third experiment investigated whether the difference was attributable to differences in psychophysical method or in method of presentation. Five subjects performed magnitude estimation listening with headphones, with a resultant exponent of 1.70. An experiment on the detection of the presence of vibrate confirmed that there is a significant difference between perceiving vibrato with headphones and from a speaker in a room. Sixteen subjects in a room were performing in a 2AFC task at the 83% correct level at a width of ± 2 cent, whereas ten subjects with headphones were able to score only 68% correct at a width of ± 10 cent.