Can background noise increase the informational masking in a speech mixture?

This study tested the hypothesis that adding noise to a speech mixture may cause both energetic masking by obscuring parts of the target message and informational masking by impeding the segregation of competing voices. The stimulus was the combination of two talkers-one target and one masker-presented either in quiet or in noise. Target intelligibility was measured in this mixture and for conditions in which the speech was "glimpsed" in order to quantify the energetic masking present. The results suggested that the addition of background noise exacerbated informational masking, primarily by increasing the sparseness of the speech.