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

Non-native (L2) speakers of English often experience difficulties in producing English interdental fricatives (e.g. the voiceless [θ]), and this leads to frequent substitutions of these fricatives (e.g. with [t], [s], and [f]). Differences in the choice of [θ]-substitutions across L2 speakers with different native (L1) language backgrounds have been extensively explored. However, even within one foreign accent, more than one substitution choice occurs, but this has been less systematically studied. Furthermore, little is known about whether the substitutions of voiceless [θ] are phonetically clear instances of [t], [s], and [f], as they are often labelled. In this study, we attempted a phonetic approach to examine language-specific preferences for [θ]-substitutions by carrying out acoustic measurements of L1 and L2 realizations of these sounds. To this end, we collected a corpus of spoken English with L1 speakers (UK-English), and Dutch and German L2 speakers. We show a) that the distribution of differential substitutions using identical materials differs between Dutch and German L2 speakers, b) that [t,s,f]-substitutes differ acoustically from intended [t,s,f], and c) that L2 productions of [θ] are acoustically comparable to L1 productions

Word recognition in possible word contexts

The Possible-Word Constraint (PWC; Norris, McQueen, Cutler, and Butterfield 1997) suggests that segmentation of continuous speech operates with a universal constraint that feasible words should contain a vowel. Single consonants, because they do not constitute syllables, are treated as non-viable residues. Two word-spotting experiments are reported that investigate whether the PWC really is a language-universal principle. According to the PWC, Slovak listeners should, just like Germans, be slower at spotting words in single consonant contexts (not feasible words) as compared to syllable contexts (feasible words)—even if single consonants can be words in Slovak. The results confirm the PWC in German but not in Slovak

"Sink positive": Experience with foreign accents influences native and non-native word recognition

Spoken language contains extensive variability in pronunciation. Effects of mispronunciations (e.g., /s/ instead of / production in theft) on word recognition are often explained in terms of perceptual similarity: the less similar mispronunciations are to target words, the more lexical activation is disturbed (Connine, Blasko, & Titone, 1993). Recent research suggests that recognition of phonological variants is also modulated by production frequency (e.g., the nasal flapped variant in a production of gentle in American English): frequent variant forms are recognized more easily than infrequent ones (Ranbom & Connine, 2008). The aim of the present study was to compare the relative influence of perceptual similarity with that of production frequency on native and non-native recognition of mispronounced words in foreign -accented speech. We used th-mispronunciations that occur regularly in foreign-accented English with varying frequency for different speaker groups. In a production study, we showed that while Dutch speakers of English frequently substitute voiceless th with /t/ (e.g., /tεft/ for theft, 80% of the mispronunciations), German speakers prefer /s/ (e.g., /sεft/, 71% of the mispronunciations); the perceptually close /f/ occurs infrequently in both groups (10% and 12%). Contrary to non-native speakers, native English speakers have mainly experience with the /f/ substitute, which occurs in some English dialects. Five eye-tracking experiments then examined whether frequent or perceptually similar substitutions cause stronger lexical activation during word recognition than infrequent or less similar ones. Advanced German and Dutch learners of English as well as native English participants listened to English sentences spoken with a German or Dutch accent (e.g., "Now you will hear /tεft/"), while they were looking at a display with four printed words; displays showed a potential match/target for the mispronunciation (theft), a competitor that also differed from the speech input only in onset (left), and two unrelated distractors (kiss, mask). The time course of lexical activation was measured as a function of amount of looks to printed th-words after hearing mispronounced words with a /t/, /s/, or /f/ substitute. Irrespective of the heard accent, all three substitutes always led to significantly more fixations to the th-words than to any of the competitors or distractors. This suggests that listeners can recognize mispronounced words, even when the substitutes occur infrequently in their own non-native speech. Furthermore, for Dutch listeners th-words were fixated over time most often when hearing /t/-substitutes, and for German listeners when hearing /s/-substitutes, while /f/ never outperformed the accent-specific dominant substitute. Native listeners, however, preferably fixated th-words after the perceptually similar substitute /f/. A correlation analysis with fixation probabilities and participants' production data did not show any effects, suggesting that individual productions do not necessarily drive the observed effects. The results show that word recognition is influenced by linguistic experience with mispronounced instances of words that vary for different foreign-accents; and effects of production frequency can outweigh perceptual similarity in the recognition of non-native mispronounced words

Electrophysiological correlates of morphosyntactic integration in German phrasal context

The morphosyntactic paradigm of an inflected word can influence isolated word recognition, but its role in multiple-word phrasal integration is less clear. We examined the electrophysiological response to adjectives in short German prepositional phrases to evaluate whether strong and weak forms of the adjective show a differential response, and whether paradigm variables are related to this response. Twenty native German speakers classified serially presented phrases as grammatically correct or not while the electroencephalogram (EEG) was recorded. A functional mixed effects model of the response to grammatically correct trials revealed a differential response to strong and weak forms of the adjectives. This response difference depended on whether the preceding preposition imposed accusative or dative case. The lexically conditioned information content of the adjectives modulated a later interval of the response. The results indicate that grammatical context modulates the response to morphosyntactic information content, and lends support to the role of paradigm structure in integrative phrasal processing

Individual differences in the acquisition of a complex L2 phonology: A training study

Many learners of a foreign language (L2) struggle to correctly pronounce newly-learned speech sounds, yet many others achieve this with apparent ease. Here we explored how a training study of learning complex consonant clusters at the very onset of the L2 acquisition can inform us about L2 learning in general and individual differences in particular. To this end, adult Dutch native speakers were trained on Slovak words with complex consonant clusters (e.g., pstruh /pstrux/‘trout’, štvrť /ʃtvrc/ ‘quarter’) using auditory and orthographic input. In the same session following training, participants were tested on a battery of L2 perception and production tasks. The battery of L2 tests was repeated twice more with one week between each session. In the first session, an additional battery of control tests was used to test participants’ native language (L1) skills. Overall, in line with some previous research, participants showed only weak learning effects across the L2 perception tasks. However, there were considerable individual differences across all L2 tasks, which remained stable across sessions. Only two participants showed overall high L2 production performance that fell within 2 standard deviations of the mean ratings obtained for an L1 speaker. The mispronunciation detection task was the only perception task which significantly predicted production performance in the final session. We conclude by discussing several recommendations for future L2 learning studies

Lexical segmentation in Slovak and German

All humans are equipped with perceptual and articulatory mechanisms which (in healthy humans) allow them to learn to perceive and produce speech. One basic question in psycholinguistics is whether humans share similar underlying processing mechanisms for all languages, or whether these are fundamentally different due to the diversity of languages and speakers. This book provides a cross-linguistic examination of speech comprehension by investigating word recognition in users of different languages. The focus is on how listeners segment the quasi-continuous stream of sounds that they hear into a sequence of discrete words, and how a universal segmentation principle, the Possible Word Constraint, applies in the recognition of Slovak and German