ABSTRACT
Speech communications are seldom isolated auditory events in quiet envi ronments. Frequently, the desired speech signal is confounded with other speech signals and noises. Real-world environments often degrade the intelligibility of the desired speech signal. In this chapter, the literature on the speech intelligibility of competing messages and the masking of speech is reviewed. The literature on the detection of speech is included to describe factors that can affect speech intelligibility. Following the review, several experiments are presented in which the effects of various conflicting signals on speech communications are measured. Virtual audio over headphones is used to investigate the effects of directional separation of talkers, the quantity and gender of talkers, the degree of masker interaural correlation, masking level, and selective attention. The results are discussed and com pared with the previous literature.
