posted on 2015-06-01, 00:00authored byLionel Fontan, Julien Tardieu, Pascal Gaillard, Virginie Woisard, Robert Ruiz
Purpose The authors investigated the relationship between the intelligibility and comprehension of speech presented in babble noise.
Method Forty participants listened to French imperative sentences (commands for moving objects) in a multitalker babble background for which intensity was experimentally controlled. Participants were instructed to transcribe what they heard and obey the commands in an interactive environment set up for this purpose. The former test provided intelligibility scores and the latter provided comprehension scores.
Results Collected data revealed a globally weak correlation between intelligibility and comprehension scores (r = .35, p < .001). The discrepancy tended to grow as noise level increased. An analysis of standard deviations showed that variability in comprehension scores increased linearly with noise level, whereas higher variability in intelligibility scores was found for moderate noise level conditions.
Conclusion These results support the hypothesis that intelligibility scores are poor predictors of listeners' comprehension in real communication situations. Intelligibility and comprehension scores appear to provide different insights, the first measure being centered on speech signal transfer and the second on communicative performance. Both theoretical and practical implications for the use of speech intelligibility tests as indicators of speakers' performances are discussed.
Funding
The picture set used in this study has been reproduced with the permission of QA International (http://www.ikonet.com) from the book�The Visual Dictionary. � QA International, 2003. All rights reserved. The authors wish to express special thanks to Matt Coler for helpful comments on an earlier version of this article.