End-to-End Acoustic Feedback in Language Learning for Correcting Devoiced French Final-Fricatives

International audienceThis work aims at providing an end-to-end acoustic feedback framework to help learners of French to pronounce voiced frica-tives. A classifier ensemble detects voiced/unvoiced utterances, then a correction method is proposed to improve the perception and production of voiced fricatives in a word-final position. Realizations of voiced fricatives contained in French sentences uttered by French and German speakers were analyzed to find out the deviations between the acoustic cues realized by the two groups of speakers. The correction method consists in substituting the erroneous devoiced fricative by TD-PSOLA concate-native synthesis that uses exemplars of voiced fricatives chosen from a French speaker corpus. To achieve a seamless concatena-tion the energy of the replacement fricative was adjusted with respect to the energy levels of the learner's and French speaker's preceding vowels. Finally, a perception experiment with the corrected stimuli has been carried out with French native speakers to check the appropriateness of the fricative revoicing. The results showed that the proposed revoicing strategy proved to be very efficient and can be used as an acoustic feedback

French Learners of L2 English: Intonation Boundaries and the Marking of Lexical Stress

To test my hypothesis, I collected passages of read speech by thirteen upper intermediate/advanced French learners of English along with the same passage read by ten native English speakers. Two trisyllabics carrying primary stress on the second syllable (com'puter, pro'tection) were placed in a series of intonational contexts under observation. The test-words were then extracted and submitted to native English listeners. The perceptual results show that the predicted ‘challenging’ contexts indeed caused substantial instability in the learners’ placement of lexical stress as perceived by native English listeners

Monitoring English Sandhi Linking – A Study of Polish Listeners’ L2 Perception

This paper presents a set of word monitoring experiments with Polish learners of English. Listeners heard short recordings of native English speech, and were instructed to respond when they recognized an English target word that had been presented on a computer screen. Owing to phonological considerations, we compared reaction times to two types of vowel-initial words, which had been produced either with glottalization, or had been joined via sandhi linking processes to the preceding word. Results showed that the effects of the glottalization as a boundary cue were less robust than expected. Implications of these findings for models of L2 speech are discussed. It is suggested that the prevalence of glottalization in L1 production makes listeners less sensitive to its effects as a boundary cue in L2

Turkish /h/ deletion : evidence for the interplay of speech perception and phonology

It has been hypothesized that sounds which are less perceptible are more likely to be altered than more salient sounds, the rationale being that the loss of information resulting from a change in a sound which is difficult to perceive is not as great as the loss resulting from a change in a more salient sound. Kohler (1990) suggested that the tendency to reduce articulatory movements is countered by perceptual and social constraints, finding that fricatives are relatively resistant to reduction in colloquial German. Kohler hypothesized that this is due to the perceptual salience of fricatives, a hypothesis which was supported by the results of a perception experiment by Hura, Lindblom, and Diehl (1992). These studies showed that the relative salience of speech sounds is relevant to explaining phonological behavior. An additional factor is the impact of different acoustic environments on the perceptibility of speech sounds. Steriade (1997) found that voicing contrasts are more common in positions where more cues to voicing are available. The P-map, proposed by Steriade (2001a, b), allows the representation of varying salience of segments in different contexts. Many researchers have posited a relationship between speech perception and phonology. The purpose of this paper is to provide experimental evidence for this relationship, drawing on the case of Turkish /h/ deletion

Pauses and the temporal structure of speech

Natural-sounding speech synthesis requires close control over the temporal structure of the speech flow. This includes a full predictive scheme for the durational structure and in particuliar the prolongation of final syllables of lexemes as well as for the pausal structure in the utterance. In this chapter, a description of the temporal structure and the summary of the numerous factors that modify it are presented. In the second part, predictive schemes for the temporal structure of speech ("performance structures") are introduced, and their potential for characterising the overall prosodic structure of speech is demonstrated

Laryngeal stop systems in contact: connecting present-day acquisition findings and historical contact hypotheses

This article examines the linguistic forces at work in present-day second language and bilingual acquisition of laryngeal contrasts, and to what extent these can give us insight into the origin of laryngeal systems of Germanic voicing languages like Dutch, with its contrast between prevoiced and unaspirated stops. The results of present-day child and adult second language acquisition studies reveal that both imposition and borrowing may occur when the laryngeal systems of a voicing and an aspirating language come into contact with each other. A scenario is explored in which socially dominant Germanic-speaking people came into contact with a Romance-speaking population, and borrowed the Romance stop system

Non-native contrasts in Tongan loans

We present three case studies of marginal contrasts in Tongan loans from English, working with data from three speakers. Although Tongan lacks contrasts in stress or in CC vs. CVC sequences, secondary stress in loans is contrastive, and is sensitive to whether a vowel has a correspondent in the English source word; vowel deletion is also sensitive to whether a vowel is epenthetic as compared to the English source; and final vowel length is sensitive to whether the penultimate vowel is epenthetic, and if not, whether it corresponds to a stressed or unstressed vowel in the English source. We provide an analysis in the multilevel model of Boersma (1998) and Boersma & Hamann (2009), and show that the loan patterns can be captured using only constraints that plausibly are needed for native-word phonology, including constraints that reflect perceptual strategies

Phonological Factors Affecting L1 Phonetic Realization of Proficient Polish Users of English

Acoustic phonetic studies examine the L1 of Polish speakers with professional level proficiency in English. The studies include two tasks, a production task carried out entirely in Polish and a phonetic code-switching task in which speakers insert target Polish words or phrases into an English carrier. Additionally, two phonetic parameters are studied: the oft-investigated VOT, as well as glottalization vs. sandhi linking of word-initial vowels. In monolingual Polish mode, L2 interference was observed for the VOT parameter, but not for sandhi linking. It is suggested that this discrepancy may be related to the differing phonological status of the two phonetic parameters. In the code-switching tasks, VOTs were on the whole more English-like than in monolingual mode, but this appeared to be a matter of individual performance. An increase in the rate of sandhi linking in the code-switches, except for the case of one speaker, appeared to be a function of accelerated production of L1 target items

Where is the length effect? A cross-linguistic study.

Many models of speech production assume that one cannot begin to articulate a word before all its segmental units are inserted into the articulatory plan. Moreover, some of these models assume that segments are serially inserted from left to right. As a consequence, latencies to name words should increase with word length. In a series of five experiments, however, we showed that the time to name a picture or retrieve a word associated with a symbol is not affected by the length of the word. Experiments 1 and 2 used French materials and participants, while Experiments 3, 4 and 5 were conducted with English materials and participants. These results are discussed in relation to current models of speech production, and previous reports of length effects are reevaluated in light of these findings. We conclude that if words are encoded serially, then articulation can start before an entire phonological word has been encoded

Teaching the pronunciation of sentence final and word boundary stops to French learners of English: distracted imitation versus audio-visual explanations.

Studies on stop unrelease in second language acquisition have hitherto focused on the productions of Slavic learners of English (Šimáčková & Podlipský, 2015) and experiments on Polish learners of English; the latter show the tendency to release stops on a more regular basis depending on the type of stop combinations (Rojczyk et al. 2013). In the present study, we aim to test the efficiency of audio-visual explanations as opposed to distracted imitation in pronunciation teaching amongst French learners of English. While unreleased stops are rather frequent in French and English - especially in plosives clusters (Byrd, 1993; Davidson, 2010), unreleased plosives in final positions are less common in French (Van Dommelen, 1983). During phase 1 of the experiment, three groups of 12 native French learners of English (level A1/A2, B1/B2 and C1/C2) were asked to read idiomatic expressions containing both homogeneous and heterogeneous sequences of voiceless stops straddled between words, namely, in sequences like “that cat” [ðæt˺ kæt˺], and stops at the end of sentences like “I told him to speak” [tə spiːk˺]. In the second phase of the experiment, one half in each group was given a different task. The first group heard recorded versions of phase 1 sentences and before reading them out loud, counted up to five in their L1. Stimuli for imitation contained no release in the contexts under scrutiny. The other half had to watch a video explaining the phenomenon of unreleased stops with a production of phase-two expressions propped up by hand gestures. They were then asked to re-read the sentences given in phase 1. Based on these results the current study makes recommendations about what working environment should be prioritized in pronunciation teaching both in class and online (Kröger et al. 2010), and suggests ways to assess students and visually keep track of their progress