Impact of speech rate on perception of vowel and consonant duration by bilinguals and monolinguals.

The perceptual boundary between short and long categories depends on speech rate. We investigated the influence of speech rate on perceptual boundaries for short and long vowel and consonant contrasts by Spanish-English bilingual listeners and English monolinguals. Listeners tended to adapt their perceptual boundaries to speech rates, but the strategy differed between groups, especially for consonants.

Auditory discrimination in aging bilinguals vs. monolinguals with and without hearing loss.

Demands for effective assessments of speech perception specific to the aging brain are increasing, as the impacts of hearing loss on an individual's functional health, socialization, and cognition have become more widely recognized. Understanding the mechanisms behind the optimal function of the aging brain in relation to speech and language is challenging, especially in the bilingual population where the language learning and language interference processes could be mistaken for perceptual difficulty. Age-related presbycusis is unavoidable, and the contributions of this sensorineural hearing loss (SNHL) process on impaired speech recognition are not completely understood.

Perception of temporally contrasted Japanese words by Spanish-English bilinguals and American English monolinguals.

Japanese and English use temporal cues within vowels, suggesting an audio-processing advantage for temporally-cued contrasts, while Spanish does not. Using a categorial AXB discrimination task, this study investigated how American English-speaking monolinguals and early and late Spanish-English bilinguals perceive three types of temporally-contrasting Japanese pairs: vowel length (kado/kaado), consonant length (iken/ikken), and syllable number (hjaku/hijaku). All groups performed worse than Japanese controls for the vowel length and syllable number contrasts, but only early bilinguals differed from controls for consonant length.

Online Assessment of Speech Perception and Auditory Spectrotemporal Processing in Spanish-English Bilinguals.

Purpose: There is limited access to audiology services for the growing population of Spanish-English bilinguals in the United States. Online auditory testing can potentially provide a cost-effective alternative to in-person visits. However, even for bilinguals with high English proficiency, age of English acquisition may affect speech perception accuracy.

Automaticity of speech processing in early bilingual adults and children.

We examine whether early acquisition of a second language (L2) leads to native-like neural processing of phonemic contrasts that are absent in the L1. Four groups (adult and child monolingual speakers of English; adult and child early bilingual speakers of English and Spanish, exposed to both languages before 5 years of age) participated in a study comparing the English /I/ - /ε/ contrast. Neural measures of automatic change detection (Mismatch Negativity, MMN) and attention (Processing Negativity, PN and Late Negativity, LN) were measured by varying whether participants tracked the stimulus stream or not.

Second-language learning effects on automaticity of speech processing of Japanese phonetic contrasts: An MEG study.

We examined discrimination of a second-language (L2) vowel duration contrast in English learners of Japanese (JP) with different amounts of experience using the magnetoencephalography mismatch field (MMF) component. Twelve L2 learners were tested before and after a second semester of college-level JP; half attended a regular rate course and half an accelerated course with more hours per week. Results showed no significant change in MMF for either the regular or accelerated learning group from beginning to end of the course.

Neural measures of a Japanese consonant length discrimination by Japanese and American English listeners: Effects of attention.

This study examined automaticity of discrimination of a Japanese length contrast for consonants (miʃi vs. miʃʃi) in native (Japanese) and non-native (American-English) listeners using behavioral measures and the event-related potential (ERP) mismatch negativity (MMN). Attention to the auditory input was manipulated either away from the auditory input via a visual oddball task (Visual Attend), or to the input by asking the listeners to count auditory deviants (Auditory Attend).

Cross-language perceptual similarity predicts categorial discrimination of American vowels by naïve Japanese listeners.

Current speech perception models propose that relative perceptual difficulties with non-native segmental contrasts can be predicted from cross-language phonetic similarities. Japanese (J) listeners performed a categorical discrimination task in which nine contrasts (six adjacent height pairs, three front/back pairs) involving eight American (AE) vowels [iː, ɪ, ε, æː, ɑː, ʌ, ʊ, uː] in /hVbə/ disyllables were tested. The listeners also completed a perceptual assimilation task (categorization as J vowels with category goodness ratings).

Perception of Japanese temporally-cued contrasts by American English listeners.

American listeners' perception of Japanese contrasts of vowel length (e.g., kiro vs.

Perception of a Japanese vowel length contrast by Japanese and American English listeners: behavioral and electrophysiological measures.

This study examined the role of automatic selective perceptual processes in native and non-native listeners' perception of a Japanese vowel length contrast (tado vs. taado), using multiple, natural-speech tokens of each category as stimuli in a "categorial oddball" design. Mismatch negativity (MMN) was used to index discrimination of the temporally-cued vowel contrast by naïve adult American listeners and by a native Japanese-speaking control group in two experiments in which attention to the auditory input was manipulated: in Exp 1 (Visual-Attend), listeners silently counted deviants in a simultaneously-presented visual categorial oddball shape discrimination task; in Exp 2 (Auditory-Attend), listeners attended to the auditory input and implicitly counted target deviants.

Acoustic variability within and across German, French, and American English vowels: phonetic context effects.

Cross-language perception studies report influences of speech style and consonantal context on perceived similarity and discrimination of non-native vowels by inexperienced and experienced listeners. Detailed acoustic comparisons of distributions of vowels produced by native speakers of North German (NG), Parisian French (PF) and New York English (AE) in citation (di)syllables and in sentences (surrounded by labial and alveolar stops) are reported here. Results of within- and cross-language discriminant analyses reveal striking dissimilarities across languages in the spectral/temporal variation of coarticulated vowels.