Masking and the Perception of a Series of Successively Prominent Partials in a Vocal Sound Free

At the last meeting of the Society, we presented a paper dealing with a vocal sound of short duration and of essentially constant pitch and loudness whose upper partials (three to seven, inclusive) became successively and individually prominent during the course of the sound. There was no way of knowing, at the time of the previous report, whether or not masking effects were of any importance in determining how the sound was heard. Data have recently been secured on the masked absolute thresholds of each of the five crucial partials for the periods immediately preceding and immediately succeeding the period during which it was heard as prominent. Although the threshold measurements were made indirectly (that is, in relation to similar complex sounds produced with a multi‐harmonic generator), the obtained values are believed to be approximate measures of the masking introduced by the vocal sound. Masking was by no means negligible; but only the fifth partial was found to be below its masked absolute threshold. It has been concluded, therefore, that any one of the partials, except the fifth, could have been heard individually during periods proximate to its period of prominence if attention had somehow been focused upon it. Possible limitations with respect to this conclusion are apparent in view of data on the typical magnitude of masked differential thresholds. However, there is little reason for doubting that attentional factors played a predominant role in determining the manner of perceiving the successively prominent partials.