Kiyoko Yoneyama

How we hear what is hardly there: Mechanisms underlying compensation for /t/-reduction in speech comprehension

In four experiments, we investigated how listeners compensate for reduced /t/ in Dutch. Mitterer and Ernestus [Mitterer, H., & Ernestus, M. (2006). Listeners recover /t/s that speakers lenite: evidence from /t/-lenition in Dutch. Journal of Phonetics, 34, 73–103] showed that listeners are biased to perceive a /t/ more easily after /s/ than after /n/, compensating for the tendency of speakers to reduce word-final /t/ after /s/ in spontaneous conversations. We tested the robustness of this phonological context effect in perception with three very different experimental tasks: an identification task, a discrimination task with native listeners and with non-native listeners who do not have any experience with /t/-reduction, and a passive listening task (using electrophysiological dependent measures). The context effect was generally robust against these experimental manipulations, although we also observed some deviations from the overall pattern. Our combined results show that the context effect in compensation for reduced /t/ results from a complex process involving auditory constraints, phonological learning, and lexical constraints. 2008 Elsevier Inc. All rights reserved.

A cross‐linguistic study of diphthongs in spoken word processing in Japanese and English

Utilizing a phoneme‐monitoring task, the current study investigates the sensitivity to moraic structure in English and Japanese diphthongs by three groups of language users: monolingual Japanese listeners, monolingual English listeners, and semibilingual Japanese speakers of English. Experiment 1 focused on monolingual Japanese listeners and found that they did not show a moraic effect in English materials, although they did not show that in Japanese materials. Experiment 2 focused on monolingual English listeners and found that they were not sensitive to moraic structure in either English or Japanese, and seemed to listen to both English and Japanese in the same listening strategy. Experiment 3 focused semibilingual Japanese speakers of English and found that they showed a moraic effect in Japanese materials while they did not in English materials. Collectively, findings in experiments 1 and 3 suggest that Japanese natives are generally sensitive to moraic structure. Also, those in experiment 1 and 2 suggest that sensitivity to moraic structure is language specific. Finally, those in experiment 3 suggest that extensive second‐language experience allows one to readjust this tuning for each language spoken, such that a listener’s speech segmentation strategy can differ by language.

An instance‐based model of Japanese speech recognition by native and non‐native listeners

Japanese has a short and long segment contrast (oji‐san versus ojii‐san, kita versus kitta, and kana versus kanna). Previous research has shown that this durational property is one of the characteristics of moras in Japanese. It has also been reported that Japanese learners generally have difficulty in acquiring this contrast, but after extensive language experience with Japanese, they do learn the contrast. This suggests that the contrasts and similarities are based on remembered instances of linguistic objects in various environments during a lifetime. This paper investigates whether an instance‐based approach of speech recognition can replicate performance by native listeners and second language learners of Japanese. An instance‐based model was trained with naturally produced utterances of koma spin and komma comma and then tested on a 24‐step nasal duration continuum from koma to komma [T. Uchida, doctoral dissertation, Nagoya University (1996)]. The identification function produced by the model was v...

Non‐native listeners’ representations of within‐word structure

Human listeners may form conscious representations of potential within‐word structure in which lexicon is represented by some phonological units. An earlier study examining monolingual speakers of Japanese and English with native inputs suggests that levels of representation by Japanese speakers may be involved with richer knowledge of word‐internal structure, while English speakers are sensitive to syllables [Otake et al., Proceedings of EUROSPEECH 95 3, 1703–1706 (1995)]. The present study investigated how monolingual speakers of English learning Japanese could form conscious representations of potential within‐word structure in Japanese. Three groups of subjects (N: 36, 33, and 40 for three different levels) were presented with 150 Japanese spoken words and asked to mark on a written transcript of each word the second natural division point from the onset in the word. The statistical analysis showed that all groups exploited syllables to represent Japanese words irrespective of Japanese proficiency. Th...

Age- and gender-related variation in voiced stop prenasalization in Japanese

Modern Japanese is generally described as having phonologically voiced (versus voiceless) word-initial stops. However, phonetic details vary across dialects and age groups; in Takadas (2011) measurements of recordings of 456 talkers from multiple generations of talkers across five dialects, Osaka-area speakers and older speakers in the Tokyo area (Tokyo, Chiba, Saitama, and Kanagawa prefectures) typically show pre-voicing (lead VOT), but younger speakers show many “devoiced” (short lag VOT) values, a tendency that is especially pronounced among younger Tokyo-area females. There is also variation in the duration of the voice bar, with very long values (up to -200 ms lead VOT) observed in the oldest female speakers. Spectrograms of such tokens show faint formants during the stop closure, suggesting a velum-lowering gesture to vent supra-glottal air pressure to sustain vocal fold vibration. Further evidence of pre-nasalization in older Tokyo-area females comes from comparing amplitude trajectories for the voice bar to amplitude trajectories during nasal consonants, adapting a method proposed by Burton, Blumstein, and Stevens (1972) for exploring phonemic pre-nasalization contrasts. Differences in trajectory shape patterns between the oldest males and females and between older and younger females are like the differences that Kong, Syrika, and Edwards (2012) observed across Greek dialects.

An effect of phoneme frequency on stop place perception by English‐speaking and Japanese‐speaking listeners.

The effects of phoneme frequency on stop place perception were examined. In English, [t] is more frequently observed than [k] while the opposite is true in Japanese. If the sound frequency affects the phoneme perception, English listeners would identify more of the ambiguous [t]‐[k] stimuli as “t” than do Japanese listeners. In this study, a 4IAX discrimination experiment and a phoneme boundary decision experiment were conducted with English‐speaking and Japanese‐speaking listeners to test this hypothesis. The stimuli of the two experiments were created by the Klatt synthesizer. [ta], [ka], [to], and [ko] were recorded by a native Japanese speaker and a native English speaker, respectively. Then, [ta], [ka], [to], and [ko] were synthesized based on the parameter values obtained from the measurements of the recorded tokens. They were used as the end‐point tokens of a nine‐step continuum. The rest of the tokens were created by manipulating frequency parameters of the synthesizer. Four sets of [k]‐[t] contin...

Neighborhood effects in Japanese word recognition

This paper reports on the results of a naming experiment that investigated lexical neighborhood effects in Japanese word recognition. A naming experiment was conducted with 28 Japanese adult listeners. Each participant responded to 700 words that had varying neighborhood density (in terms of Greenberg–Jenkins’ phoneme substitution, deletion, and insertion rules). The lexicon used for this calculation consisted of only nouns from the NTT Japanese psycholinguistic database [Amano and Kondo (1999)]. A preliminary regression analysis showed that such neighborhood density was negatively correlated with naming reacting time. The words with higher neighborhood density were responded to faster than those with lower neighborhood density. We plan to report further analyses that (1) include prosodic information as another dimension of the neighborhood calculation in order to reflect the finding that prosodic information has a vital role in Japanese word recognition, and that (2) calculate neighborhood density based ...

Perception of American English alveolar stops and flaps by Japanese learners of English: Does allophonic variation matter?

A lexical decision experiment was conducted with Japanese learners of English with relatively low English proficiency to investigate whether second-language (L2) learners utilize allophonic variation when recognizing words in L2. The stimuli consisted of 36 isolated bisyllabic words containing word-medial /t/, half of which were flap-favored words (e.g., better, city) and the other half were [t]-favored words (e.g., faster, custom). All stimuli were recorded with two surface forms: /t/ as a flap (e.g., better with a flap) or as [t] (e.g., better with [t]). The stimuli were counterbalanced in the lists using a Latin Square design, so that participants only heard one of the two surface forms. The accuracy data indicated that flap-favored words pronounced with a flap (e.g, city with a flap) were recognized significantly less accurately than [t]-favored words with a flap (e.g., faster with a flap) and [t]-favored words with [t] (e.g., faster with [t]). These results suggest that Japanese learners prefer canon...

Foreign accentedness of English sentences spoken by Japanese EFL learners and Japanese teachers of English: A first report

This study reports the results of a foreign-accented-rating experiment that investigate the foreign accentedness of spoken English sentences by two Japanese groups, Japanese EFL learners and Japanese teachers of English. This study aims first to investigate whether spoken English sentences by Japanese teachers of English are judged less foreign-accented than those by Japanese EFL learners, and second to investigate whether American-English listeners rate spoken English sentences by Japanese speakers more severely than Japanese listeners do. The stimuli were five sentences adopted from Flege, Munro, and McKay (1995) spoken by 33 Japanese EFL learners and 33 Japanese teachers of English. Ten American-English speakers and ten Japanese speakers were asked to rate the stimuli presented visually and auditorily by clicking along a line on the computer screen for their ratings. The participants’ original responses were converted to 10 scales and were submitted to the analyses. The results showed that spoken Engli...

Production of a non-phonemic variant in a second language: Acoustic analysis of Japanese speakers’ production of American English flap

Second-language (L2) learners need to learn the sound system of an L2 so that they can distinguish L2 words. However, it is also instructive to learn non-phonemic, allophonic variations, particularly if learners want to sound native-like. The production of intervocalic /t d/ as an alveolar flap is a prime example of a non-phonemic variation that is salient in American English and presumably noticeable to many L2 learners. Yet, how well such non-phonemic variants are learned by L2 learners is a relatively under-explored subject. In the present study, Japanese learners’ production of alveolar flaps was investigated, to clarify how well learners can learn the phonetic environments in which flapping tends to occur, and how L2 experience affects their performance. Native Japanese speakers who had lived in North America for various lengths of time read a list of words and phrases that contained a potentially flappable stop, embedded in a carrier sentence. Preliminary results indicated that the rate of flapping varied considerably across different words and phrases and across speakers. Furthermore, acoustic parameters such as flap closure duration produced by some speakers showed intermediate values between native-like flaps and regular stops, suggesting that flapping is a gradient phenomenon. [Work supported by JSPS.]