Click Heard when a Musical Tone Makes an Abrupt Frequency Change
Herbert M. Neustadt · The Journal of the Acoustical Society of America · 1965
Development work on new electronic musical instruments has revealed that (1) the ear hears a click when a musical tone makes an abrupt frequency shift; (2) the click is prominently loud when the shift is over a range as large as an octave, but barely perceptible when the range is as small as a semitone; (3) the click is sometimes absent in the sound output of a wind musical instrument making a large abrupt frequency change; (4) the only way that such a clickfree frequency change can be made is by means of a simultaneous interruption of amplitude; (5) when a large frequency change is accompanied by a properly shaped simultaneous interruption of amplitude, the ear hears no click and does not perceive the amplitude interruption. These facts are demonstrated with the aid of an electronic tone source. It is shown that the click sensation can be plausibly explained by considering it to be the readout of a fast-acting frequency analyzer. [Electronic tone source used for elucidating the click was built with support from the U. S. Office of Naval Research.]