Time-compressed speech perception with speech and noise maskers

Many researchers have shown that speech signals can be time compressed (TC) by a factor of two or more without a significant loss in intelligibility. However, most previous studies with TC speech have been conducted either in quiet or, in a very small number of cases, with noise maskers. In this experiment, we examine the effect that TC has on the perception of a speech signal in the presence of a speech or noise masker. The results show that normal speech can be accelerated a modest amount (20-30%) without increased susceptibility to masking, but that higher TC ratios can lead to dramatically worse performance in the presence of an interfering sound. The results also indicate that time-expansion can, in some cases, lead to improved performance when a listener is attending to the quieter of two talkers in an auditory mixture. These results suggest that there are some important practical limitations on how TC should be used to enhance communications efficiency in auditory speech displays.