Strategies adopted by talkers faced with fluctuating and competing-speech maskers

Studying how interlocutors exchange information efficiently during conversations in less-than-ideal acoustic conditions promises to both further the understanding of links between perception and production and inform the design of human-computer dialogue systems. The current study explored how interlocutors' speech changes in the presence of fluctuating noise. Pairs of talkers were recorded while solving puzzles cooperatively in quiet and with modulated-noise or competing speech maskers whose silent intervals were manipulated to produce either temporally sparse or dense maskers. Talkers responded to masked conditions by both increasing the amount of speech produced and locally changing their speech activity patterns, resulting in a net reduction in the proportion of speech in temporal overlap with the maskers, with larger relative reductions for sparse maskers. An analysis of talker activity in the vicinity of masker onset and offset events showed a significant reduction in onsets following masker onsets, and a similar increase in onsets following masker offsets. These findings demonstrate that talkers are sensitive to masking noise and respond to its fluctuations by adopting a "wait-and-talk" strategy. (C) 2013 Acoustical Society of America.