The Loudness of Repeated Short Tones

Abstract

The relation between loudness and the repetition rate of short tones was experimentally determined. The effects of intensity, frequency, and tone duration on this relation were also studied. The results can be summarized as follows. (1) A series of repeated short tones can be louder than a steady tone of the same peak intensity. (2) The difference between the loudness of repeated tones and a steady tone of the same intensity is dependent on both frequency and intensity. (3) Two series of repeated tones, of the same frequency and intensity, will not have the same loudness unless their repetition rates and durations are the same. At high intensities, the tones with the faster repetition rate and shorter duration are louder, and conversely at low intensities. (4) The rate at which loudness increases with repetition rate is dependent on the duration. The shorter the duration, the greater the change in loudness with a change in repetition rate; and conversely, the slower the repetition rate, the greater the change in loudness with a change in duration. All of the relations shown are understandable in terms of the shape of the loudness function, and the complex spectra of repeated short tones. Calculated loudness levels, according to the method of Fletcher and Munson for calculating the loudness of multicomponent tones, agree very well with the observed loudness levels.