L1 perceptions of L2 prosody: The interplay between intonation, rhythm, and speech rate and their contribution to accentedness and comprehensibility

This study investigates the cumulative effect of (non-)native intonation, rhythm, and speech rate in utterances produced by Spanish learners of Dutch on Dutch native listeners’ perceptions. In order to assess the relative contribution of these language-specific properties to perceived accentedness and comprehensibility, speech produced by Spanish learners of Dutch was manipulated using transplantation and resynthesis techniques. Thus, eight manipulation conditions reflecting all possible combinations of L1 and L2 intonation, rhythm, and speech rate were created, resulting in 320 utterances that were rated by 50 Dutch natives on their degree of foreign accent and ease of comprehensibility.
Our analyses show that all manipulations result in lower accentedness and higher comprehensibility ratings. Moreover, both measures are not affected in the same way by different combinations of prosodic features: For accentedness, Dutch listeners appear most influenced by intonation, and intonation combined with speech rate. This holds for comprehensibility ratings as well, but here the combination of all three properties, including rhythm, also significantly affects ratings by native speakers. Thus, our study reaffirms the importance of differentiating between different aspects of perception and provides insight into those features that are most likely to affect how native speakers perceive second language learners.