Perception of temporally interrupted speech: Effects of two concurrent gating rates on intelligibility.
Valeriy Shafiro, Stanley Sheft, Robert Risley · The Journal of the Acoustical Society of America · 2010
Perception of temporally interrupted speech was investigated with either one or two concurrent square-wave gating functions. Sentences were interrupted at a single rate of 1, 2, 4, 8, 16, 24, or 32 Hz with a 50% duty cycle. For each rate between 1 to 8 Hz, stimuli were additionally gated at a secondary rate ranging from twice the primary rate up to 32 Hz. The secondary gating rate thus interrupted only the segments of speech which were left intact after application of the primary gating function to reduce by half the remaining speech content independent of secondary rate. With a single gating function, intelligibility scores increased with rate, reaching perfect accuracy at 8 Hz. Application of the second gating function led to a decrease in intelligibility which was greatest when the secondary rate was twice the primary rate, a condition equivalent to a 25% duty cycle of the primary rate. Further increase in the secondary rate generally led to an improvement in intelligibility, although never to the level achieved with the primary rate alone. The incomplete recovery of intelligibility scores at fast secondary gating rates suggest disruption of separate perceptual processes by each of the two concurrent interruption rates.