Acoustic Correlates of Word Stress as A Cue to Accent Strength

Due to the clear interference of their mother tongue prosody, many Czech learners produce their English with a conspicuous foreign accent. The goal of the present study is to investigate the acoustic cues that differentiate stressed and unstressed syllabic nuclei and identify individual details concerning their contribution to the specific sound of Czech English. Speech production of sixteen female non-professional Czech and British speakers was analysed with the sounds segmented on a word and phone level and with both canonical and actual stress positions manually marked. Prior to analyses the strength of the foreign accent was assessed in a perception test. Subsequently, stressed and unstressed vowels were measured with respect to their duration, amplitude, fundamental frequency and spectral slope. Our results show that, in general, Czech speakers use much less acoustic marking of stress than the British subjects. The difference is most prominent in the domains of fundamental frequency and amplitude. The Czech speakers also deviate from the canonical placement of stress, shifting it frequently to the first syllable. On the other hand, they seem to approximate the needed durational difference quite successfully. These outcomes support the concept of language interference since they correspond with the existing linguistic knowledge about Czech and English word stress. The study adds specific details concerning the extent of this interference in four acoustic dimensions

Relative Salience of Speech Rhythm and Speech Rate on Perceived Foreign Accent in a Second Language

We investigated the independent contribution of speech rate and speech rhythm to perceived foreign accent. To address this issue we used a resynthesis technique that allows neutralizing segmental and tonal idiosyncrasies between identical sentences produced by French learners of English at different proficiency levels and maintaining the idiosyncrasies pertaining to prosodic timing patterns. We created stimuli that (1) preserved the idiosyncrasies in speech rhythm while controlling for the differences in speech rate between the utterances; (2) preserved the idiosyncrasies in speech rate while controlling for the differences in speech rhythm between the utterances; and (3) preserved the idiosyncrasies both in speech rate and speech rhythm. All the stimuli were created in intoned (with imposed intonational contour) and flat (with monotonized, constant F0) conditions. The original and the resynthesized sentences were rated by native speakers of English for degree of foreign accent. We found that both speech rate and speech rhythm influence the degree of perceived foreign accent, but the effect of speech rhythm is larger than that of speech rate. We also found that intonation enhances the perception of fine differences in rhythmic patterns but reduces the perceptual salience of fine differences in speech rate

Corsican French questions: is there a prosodic transfer from Corsican to French and how to highlight it?

Poster, 4 pagesInternational audienceThis study investigates whether a prosodic transfer can be highlighted from Corsican (an Italo-Romance language) to French spoken in Corsica, where French is now the dominant language. A corpus of transparent sentences such as la touriste trouve la caserne (French) or a turista trova a caserna (Corsican) was designed and the productions of bilingual speakers, recorded in Corsica, were compared with the French counterparts of Parisian reference speakers. The melody of yes/no questions turns out to contrast Corsican and Corsican French (both with high tones followed by final pitch falls) and standard French (with utterance-final high tones). The former pattern can be interpreted as a prosodic transfer from Corsican to French. Various methods are considered to validate this hypothesis and an experimental paradigm is proposed. Index Terms: prosody in contact, questions, Corsican accent in French, endangered languagesCette étude examine si un transfert prosodique peut être mis en évidence du Corse (une langue Italo-romane) au français parlé en Corse, où le français est maintenant la langue dominante. Un corpus de phrases simples comme touriste la trouve la caserne (français) ou a turista trova a caserna (corse) a été conçu et les productions des locuteurs bilingues, enregistré en Corse, ont été comparé aux homologues françaises de locuteurs de référence Parisiens. La mélodie des yes/no questions s'avèrent contraster le français de corse et le corse (tous deux avec de hauts tons suivis par des chutes de pic final) alors que le français standard connait des pics finaux hauts. Le contour mélogique peut être interprété comme un transfert prosodique du Corse au français. On considère diverses méthodes pour valider cette hypothèse et on propose un paradigme expérimental

An acoustic-perceptual approach to the prosody of Chinese and native speakers of Italian based on yes/no questions

The present study investigates the prosody of yes/no questions (in comparison with statements) in Chinese learners and native speakers of Italian. Acoustic analyses and a perceptual test were performed, in order to identify the main trends in non-native productions. Results show the relevance of prosody, which differentiates elementary, intermediate and advanced Chinese learners of Italian. Listening tests based on prosody transplantation also suggest that non-native segments with a native Italian prosody are rated as less accented than are native Italian segments with a non-native prosody. Similar trends were found, overall, in terms of question/assertion discrimination, confirming the relative importance of prosody. These findings could be helpful for teachers and learners of Italian as a foreign language

A computational model for studying L1’s effect on L2 speech learning

abstract: Much evidence has shown that first language (L1) plays an important role in the formation of L2 phonological system during second language (L2) learning process. This combines with the fact that different L1s have distinct phonological patterns to indicate the diverse L2 speech learning outcomes for speakers from different L1 backgrounds. This dissertation hypothesizes that phonological distances between accented speech and speakers' L1 speech are also correlated with perceived accentedness, and the correlations are negative for some phonological properties. Moreover, contrastive phonological distinctions between L1s and L2 will manifest themselves in the accented speech produced by speaker from these L1s. To test the hypotheses, this study comes up with a computational model to analyze the accented speech properties in both segmental (short-term speech measurements on short-segment or phoneme level) and suprasegmental (long-term speech measurements on word, long-segment, or sentence level) feature space. The benefit of using a computational model is that it enables quantitative analysis of L1's effect on accent in terms of different phonological properties. The core parts of this computational model are feature extraction schemes to extract pronunciation and prosody representation of accented speech based on existing techniques in speech processing field. Correlation analysis on both segmental and suprasegmental feature space is conducted to look into the relationship between acoustic measurements related to L1s and perceived accentedness across several L1s. Multiple regression analysis is employed to investigate how the L1's effect impacts the perception of foreign accent, and how accented speech produced by speakers from different L1s behaves distinctly on segmental and suprasegmental feature spaces. Results unveil the potential application of the methodology in this study to provide quantitative analysis of accented speech, and extend current studies in L2 speech learning theory to large scale. Practically, this study further shows that the computational model proposed in this study can benefit automatic accentedness evaluation system by adding features related to speakers' L1s.Dissertation/ThesisDoctoral Dissertation Speech and Hearing Science 201

The Perceptual Effect of L1 Prosody Transplantation on L2 Speech: The Case of French Accented German

Research has shown that language learners are not only challenged by segmental differences between their native language (L1) and the second language (L2). They also have problems with the correct production of suprasegmental structures, like phone/syllable duration and the realization of pitch. These difficulties often lead to a perceptible foreign accent. This study investigates the influence of prosody transplantation on foreign accent ratings. Syllable duration and pitch contour were transferred from utterances of a male and female German native speaker to utterances of ten French native speakers speaking German. Acoustic measurements show that French learners spoke with a significantly lower speaking rate. As expected, results of a perception experiment judging the accentedness of 1) German native utterances, 2) unmanipulated and 3) manipulated utterances of French learners of German suggest that the transplantation of the prosodic features syllable duration and pitch leads to a decrease in accentedness rating. These findings confirm results found in similar studies investigating prosody transplantation with different L1 and L2 and provide a beneficial technique for (computer-assisted) pronunciation training

Disentangling accent from comprehensibility

The goal of this study was to determine which linguistic aspects of second language speech are related to accent and which to comprehensibility. To address this goal, 19 different speech measures in the oral productions of 40 native French speakers of English were examined in relation to accent and comprehensibility, as rated by 60 novice raters and three experienced teachers. Results showed that both constructs were associated with many speech measures, but that accent was uniquely related to aspects of phonology, including rhythm and segmental and syllable structure accuracy, while comprehensibility was chiefly linked to grammatical accuracy and lexical richness