1 Production of English interdental fricatives by Dutch, German, and English speakers

Interdental fricatives are often difficult to produce for non-native speakers (L2) of English. German and European-French learners of English, for example, often replace the voiceless interdental fricative /T / with /s/, while Dutch and Canadian-French speakers are reported to prefer /t/. Phoneme-identification studies show that /T / is perceptually most often confused with the acoustically similar /f / by native (L1) as well as by various L2 listeners, and less frequently confused with /t / or /s / (Brannen, 2002; Cutler et al., 2004; Hancin-Bhat, 1994; Miller and Nicely, 1955; Tabain, 1998). Given the acoustic similarity with /f/, it is rather surprising that among the most common substitutions in English L2 speech are /s / and /t/, even when /f / is available in the L1 phoneme inventory of the L2 speakers. Prior research has extensively explored differences in th-substitutions across L2 learners based on the dissociation between perception and production (e.g., Brannen, 2002; Hancin-Bhat, 1994; Teasdale, 1997) and/or on phonological theories and language acquisition models (e.g., Flege and Davidian, 1984; Picard, 2002; Weinberger, 1997; Westers et al., 2007). However, even within one foreign accent and within one L2-speaker, different substitution choices are made, but these choices are less systematically studied across L2-speakers. Moreover, little is known abou