The intelligibility of Lombard speech for non-native listeners.

Speech produced in the presence of noise--Lombard speech--is more intelligible in noise than speech produced in quiet, but the origin of this advantage is poorly understood. Some of the benefit appears to arise from auditory factors such as energetic masking release, but a role for linguistic enhancements similar to those exhibited in clear speech is possible. The current study examined the effect of Lombard speech in noise and in quiet for Spanish learners of English. Non-native listeners showed a substantial benefit of Lombard speech in noise, although not quite as large as that displayed by native listeners tested on the same task in an earlier study [Lu and Cooke (2008), J. Acoust. Soc. Am. 124, 3261-3275]. The difference between the two groups is unlikely to be due to energetic masking. However, Lombard speech was less intelligible in quiet for non-native listeners than normal speech. The relatively small difference in Lombard benefit in noise for native and non-native listeners, along with the absence of Lombard benefit in quiet, suggests that any contribution of linguistic enhancements in the Lombard benefit for natives is small.