Adult Japanese Speakers Research Articles (Page 1)

The neural correlates of nominal classification rule learning and their individual differences.

This study examines how auditory spectral representations in the peripheral auditory system explain changes in vowel production under noisy conditions, especially when lower formants (F1 and F2) are masked. Ten adult male Japanese speakers produced sustained vowels /a/ and /i/ under quiet and noisy conditions involving three noise types (broadband, low-pass, and high-pass) at 75 and 85 dB. We analyzed vocal intensity and the amplitudes and frequencies of the F1 and F2. Auditory spectral representations, simulated using a loudness model, were used to estimate excitation patterns in the auditory periphery. Most noise conditions significantly increased vocal intensity and the amplitude of both formants. F1 frequency consistently shifted upward under high-intensity broadband noise, while F2 shifts depended on vowel and noise type, shifting upward for /a/ and downward for /i/. Some patterns could not be explained by power spectra alone. Instead, they were better accounted for by frequency-specific masking effects, reflected in overlapping excitation patterns in the auditory spectral representation. These overlaps indicated reduced self-audibility in specific frequency bands, triggering compensatory adjustments. The findings highlight how auditory masking influences speech production, supporting a perceptually grounded model of auditory-motor control in noisy environments.

Abstract This study explores the discourse expressivity of Chinese JFL (Japanese as a foreign language) learners’ Japanese narratives in terms of the variety and use of evaluative strategies, and analyzes how the evaluation system in their first language (L1) may be evident in their second language (L2) performance. For this reason, using the wordless picture book Frog, where are you?, we examined the oral narratives produced by adult Japanese native speakers, adult Chinese native speakers, and Chinese JFL learners. The findings suggest that the absence of “utterance attitudes” in the Chinese-language narratives is evident in the Japanese-language narratives of the Chinese JFL learners; thus, the evaluation of JFL stories is somewhat more direct, and the stories are easier to understand than those of adult JNS. However, the evaluations of the Chinese JFL learners’ narratives also diverged from those of the adult CNS in the direction of the target language’s norms.

Adult Japanese speakers often experience difficulty learning English /r/-/l/. Previous research has reported the effectiveness of using perception-based high-variability identification training with natural speech stimuli on improving Japanese speakers’ perception and production of /r/-/l/. Recent studies have also shown the effectiveness of using production-based multipronged pronunciation training with explicit instruction on articulatory movements and visualized spectrograms showing F3 frequencies of English /r/-/l/. The proposed study will compare the effects of identification training and pronunciation training on Japanese speakers’ English /r/-/l/ learning, as well as the generalization of learning gains to novel phonetic environments. Further, the proposed study will contribute to speech perception and production research by exploring the relationship between perceptual learning and production learning.

This magnetoencephaalography (MEG) study investigated the effects of language experience in cue weighting of formant structure supporting native language neural commitment. The speech stimuli were a grid of /ra-la/ synthetic continuua with systematic variations of the second (F2) and third (F3) formants. The subjects were a group of 10 monolingual adults of American English speakers and a group of 10 adult Japanese speakers. The experimental protocol adopted bi-directional oddball paradigm to examine between-group differences in discriminatory sensitivity at the pre-attentive level to stimulus conditions that featured F2 difference alone, F3 difference alone and F2 + F3 differences. Unlike previous reports, the MEG data showed equivalent amplitudes of mismatch responses for discriminating the /ra-la/ contrast in the F2 + F3 condition between the American and Japanese subjects. In the F2 difference alone condition, Japanese subjects showed enhanced discriminatory sensitivity than Amercian subjects. In the F3 difference alone condition, Japanese subjects showed reduced sensitivity than American subjects. Together, the MEG results provide strong support for an altered pattern of cue weighting that explains the native language perceptual interference in speech categorization.

High variability identification and discrimination training for Japanese speakers learning English /r/–/l/

ABSTRACTA noun can be potentially ambiguous as to whether it is a head on its own, or is a modifier of a Noun + Noun compound waiting for its head. This study investigates whether young children can exploit the prosodic information on a modifier constituent preceding the head to facilitate resolution of such ambiguity in Japanese. Evidence from English suggests that young speakers are not sensitive to compound stress in distinguishing between compounds and syntactic phrases unless the compound is very familiar (Good, 2008; Vogel & Raimy, 2002). This study concerns whether children in general have such limited capability to use prosodic cues to promptly compute a compound representation without the lexical boost, or whether they might show greater sensitivity to more categorical compound prosody such as that associated with the Compound Accent Rule (CAR) in Japanese. A previous study (Hirose & Mazuka, 2015) demonstrated that adult Japanese speakers can predict the compound structure prior to the head if the prosodic information on the modifier unambiguously signals that the CAR is being applied. The present study conducted the same on-line experiment with children (6- to 7-year-olds) and compared the time course of the effects with that of adults using permutation-based analysis (Maris & Oosternveld, 2007). The results reveal that children are sensitive to pitch accent information that facilitates the quicker processing of the compound or the single head noun representation compared to when such prosodic signals are less apparent, depending on the type of the lexical accent of the noun in question.

Center for Corpus Development, National Institute for Japanese Language and Linguistics,10–2 Midoricho, Tachikawa, Tokyo, 190–0014 Japan(Received 28 May 2012, Accepted for publication 6 July 2012)Keywords: Magnetic resonance imaging, Cine-MRI, Voiced stop consonant, Voiceless stop consonant, Tongue movementPACS number: 43.70.Aj [doi:10.1250/ast.33.391]1. IntroductionThe present study describes the transient profiles ofarticulatory movement during the pronunciation of stopconsonants using fast MRI (magnetic resonance imaging)and image processing to analyze tongue movements. Therecently developed fast scanning techniques based on MRIhave provided opportunities to observe the vocal tract shapeof every moment during speech production [1], and thus haveallowed us to reproduce speech sounds by precise, physicalacoustic modeling of the articulatory organs [2]. Theconstructive approach using physical modeling is expectedto complement conventional, descriptive studies in acousticphonetics and to reveal causal relationships between articu-latory dynamics and actual speech sounds. In contrast to thelong history of MRI studies on vowel production, however,the kinematics of the oral cavity during consonantal articu-lation has not been well studied by MRI because of thetemporal instabilities in consonantal articulation, leading todifficulties in the synthesis of natural-sounding speech byphysical modeling.Here, we measured the transient properties of vocal tractshapes by MRI during the production of rapidly changingconsonants, i.e. stop consonants, and compared them invoiced and voiceless situations. For the natural-soundingsyntheses of voiced and voiceless stops, the physical acousticmodel must reflect not only the interval between plosivereleases and vocal fold vibration (i.e., voice-onset time; VOT)but also, perhaps, secondary kinematic changes in the vocaltract accompanied with changes in VOT. For example, the airpressure in the oral cavity during the closure period forvoiceless stop consonants is higher than that for voiced stops[3,4]. This pressure difference is expected to be accompaniedwith a volume difference in the pharyngeal cavity during thestop production [5], implying supplementary changes in someacoustical features. In the present paper, we measured thevocal tract by fast MRI while participants pronounced voicedand voiceless velar stops and, in particular, we analyzed themovement trajectories of the tongue surfaces.2. Materials and methods2.1. Subjects and speech taskFour adult Japanese speakers (three males and onefemale) repeatedly uttered two nonsense words, /agise/ and/akise/; the former includes a voiced stop consonant /g/ andthe latter has a voiceless stop consonant /k/. Note that all thespeakers were Kansai dialect speakers, and hence, they didnot show the vowel deletion phenomenon on the vowel /i/following the voiceless stop consonant.2.2. Cine-MRI data acquisitionCine-MRI data of the mid-sagittal plane were acquired bya synchronized sampling method with external trigger [1].The speakers lay supine in the MRI gantry, wearing head-phones to listen to a guide sound. The guide sound was atriplet-beat sequence consisting of one tone and two noisebursts. These sound bursts had durations of 100ms, and theonset-to-onset interval was 400ms. Speakers were asked topronounce each nonsense word in synchrony with the guidesound matching the first and third morae to the second andthird beats, respectively. Each speaker uttered each worda total of 128 times during scanning. Prior to the MRIacquisition, the speakers practiced uttering the words tominimize the variation between repeated utterances to ensuresufficient quality of the cine-MRI data.The MRI acquisition was carried out using a 3T MRIscanner (MAGNETOM Verio, Siemens) at the Brain ActivityImaging Center of ATR-Promotions. The scanning parameterswere as follows. Scan sequence: FLASH, frame rate: 100frames/s, repetition time (TR): 10.0ms, echo time: 1.62ms,flip angle (FA): 15 , field of view: 256 256mm, matrixsize: 256 256, slice thickness: 4mm, without averaging.2.3. Image processing methodThe velocity of the highest point of the tongue during theproduction of the voiced and voiceless stop consonants wasmeasured from the cine-MRI data. The tongue surface wasfirst extracted from each frame of the cine-MRI data byCanny’s edge detection method [6] and was tracked using afifth-order polynomial approximation as illustrated in Fig. 1.The vertical movement and velocity of the highest point of thetongue were then calculated from the surface trajectory. Thetrajectory of the highest point of the tongue was smoothed bya sixth-order moving average and resampled at a rate of1,000 frames/s by spline interpolation. The vertical velocity

This study investigated vowel length discrimination in infants from 2 language backgrounds, Japanese and English, in which vowel length is either phonemic or nonphonemic. Experiment 1 revealed that English 18-month-olds discriminate short and long vowels although vowel length is not phonemically contrastive in English. Experiments 2 and 3 revealed that Japanese 18-month-olds also discriminate the pairs but in an asymmetric manner: They detected only the change from long to short vowel, but not the change in the opposite direction, although English infants in Experiment 1 detected the change in both directions. Experiment 4 tested Japanese 10-month-olds and revealed a symmetric pattern of discrimination similar to that of English 18-month-olds. Experiment 5 revealed that native adult Japanese speakers, unlike Japanese 18-month-old infants who are presumably still developing phonological perception, ultimately acquire a symmetrical discrimination pattern for the vowel contrasts. Taken together, our findings suggest that English 18-month-olds and Japanese 10-month-olds perceive vowel length using simple acoustic?phonetic cues, whereas Japanese 18-month-olds perceive it under the influence of the emerging native phonology, which leads to a transient asymmetric pattern in perception.

Adult Japanese speakers judged the grammaticality of simple ungramatical sentences involving two arguments, each related with a single verb. The arguments were attached to the same case marker playing the same thematic role in the sentences. Thus the sentences violated Chomsky's principle of Full Interpretation. The two arguments were manipulated such that, on the one hand, one argument (the part-argument) constituted a part of the other argument (the whole-argument) and that, on the other, a part-argument either preceded or followed a whole-argument. Participants rated the sentences using either a conventional 7-point rating scale or magnitude estimation. Findings showed that irrespective of rating method sentences in which the whole-argument preceded the part-argument were judged more grammatical than sentences in which the part-argument preceded the whole-argument. Such an empirical phenomenon is inconsistent with the prediction derived from Chomsky's principle of Full Interpretation, while interestingly it is consistent with the grammar of classical Japanese used about 900 years ago.

Whether there is an absolute critical period for acquiring language is a matter of continuous debate. One approach to address this issue is to compare the processes of second language (L2) learning after childhood and those of first language (L1) learning during childhood. To study the cortical process of postchildhood L2 learning, we compared event-related brain potentials recorded from two groups of adult Japanese speakers who attained either high or intermediate proficiency in English after childhood (J-High and J-Low), and adult native English speakers (ENG). Semantic anomalies embedded in English sentences evoked a clear N400 component in all three groups, with only the time course of the brain activation varying among the groups. Syntactic violations elicited a left-lateralized negativity similar to the left anterior negativity in ENG and J-High, but not in J-Low. In ENG, a P600 component was additionally found. These results suggest that semantic processing is robust from early on in L2 learning, whereas the development of syntactic processing is more dependent on proficiency as evidenced by the lack of the left-lateralized negativity in J-Low. Because early maturation and stability of semantic processing as opposed to syntactic processing are also a feature of L1 processing, postchildhood L2 learning may be governed by the same brain properties as those which govern childhood L1 learning. We argue that these processes are qualitatively similar in many respects, with only restricted domains of language processing being subject to absolute critical period effects.

Adult Japanese speakers judged the grammaticality of isolated simple bitransitive sentences involving an illegitimate extra argument in addition to three legitimate arguments. The sentences therefore violated Chomsky’s principle of Full Interpretation. The extra argument was a mere repetition of a preceding legitimate argument. The role of emphasis placed on the extra argument in the judgments was studied. The role of argument type, subjective and objective, was also investigated for sentences different in argument order, basic and transformed. Findings showed first that the sentences were judged moderately on a 7-point scale. Second, the transformed sentences were judged less grammatical than basic sentences. Third, sentences having two objective arguments (objective sentences) were judged more grammatical than those having two subjective arguments (subjective sentences) both for the basic and for the transformed sentences. Lastly, for the transformed sentences emphasis slightly increased the judged grammaticality of both the subjective and the objective sentences. These findings are not compatible with Chomsky’s theory of knowledge of language that he claims every speaker possesses.

Adult Japanese speakers ‘‘hear’’ epenthetic vowels in productions of Japanese-like words that violate the canonical CVCVCV form by containing internal consonant clusters (CVCCV) [Dupoux et al., J. Exp. Psychol. 25, 1568–1578 (1999)]. Given this finding, this research examined how Japanese adults rated the goodness of Japanese-like words produced without a vowel in the final syllable (CVC), and words produced without vowels in the penultimate and final syllables (CVCC). Furthermore, in some of these contexts, voiceless vowels may appear in fluent, casual Japanese productions, especially in the Kanto dialect, and in some, such voiceless vowels may not appear. Results indicate that both Kanto and Kinki speakers rated CVC productions for contexts in which voiceless vowels are not allowed as the worst; they rated CVC and CVCC contexts in which voiceless vowel productions are allowed as better. In these latter contexts, the CVC words, which result from the loss of one, final, vowel, are judged to be better than the CVCC words, which result from the loss of two (final and penultimate) vowels. These results mirror the relative seriousness of the phonotactic violations and indicate listeners have tacit knowledge of these regularities in their language.

This study aims to identify listening comprehension strategies used by adult Japanese native speakers and monolingual Australian learners of Japanese language. It investigates how two different listening contexts (audiovisual and audio-only) may influence listeners' choice of strategies and how the strategies chosen relate to learners' proficiency. In this study, a listening strategy is conceptualised as a mental operation undertaken by a learner to solve a listening comprehension problem in a non-interactional situation. To collect data on strategies, a concurrent think-aloud procedure is used and the data are analysed quantitatively. The study identified nineteen strategies which were labelled under the three general categories of ‘cognitive’ strategies (11), ‘metacognitive’ strategies (7) and ‘other’ strategies (1).

Many previous investigations of second language (L2) learning have focused on the acquisition of phonetic segments by groups of non-native speakers living in diverse regions in the US. These studies have not, however, assessed possible dialectal variation in L2 productions. The current study investigates the extent to which dialectal differences found in the vowel systems of two different American English (AE) dialects are acquired by adult Japanese speakers. Four subject groups were identified: native English speakers of a midwestern dialect of AE, native English speakers of a southern dialect of AE, Japanese speakers whose target language is a midwestern AE dialect, and Japanese speakers whose target language is a southern AE dialect. Subjects were recorded saying word and nonword utterances in isolation. Acoustic measures of vowels that can potentially capture differences between the dialects were made. These include vowel duration, and F0, F1, F2, and F3 frequencies measured at five equal distances throughout the vowel. F0–F3 measurements were used to calculate bark differences. Preliminary findings suggest that adult Japanese learners acquire some of the acoustic properties that are consistent with the dialect of the target language. [Work supported by an INRS Award from research funding from ATR (Fox, P.I.).]

Abstract Objective: The aims of this study were to examine nasalance score variation for normal adult Japanese speakers of Mid-West dialect and the gender difference in average mean nasalance score. Design: Nasalance scores were obtained using a nasometer model 6200. The sample stimulus “Kitsutsuki passage,” constructed of four sentences containing no Japanese nasal sounds, was used three times by each subject. Participants: One hundred normal adult speakers (50 women and 50 men) of Japanese served as subjects. The subjects ranged in age from 19 to 35 years of age (24.0 ± 3.2). Main Outcome Measure: A mean nasalance score as well as an overall average nasalance value across speakers was calculated for each subject. The average mean nasalance scores between men and women were compared. Results: The average mean nasalance score for the normal Japanese speakers was 9.1% (± 3.9). There was no statistically significant sex difference (p < .01). Average mean scores of 9.8% (± 3.5) and 8.3% (± 4.0) were obtained...

The aims of this study were to examine nasalance score variation for normal adult Japanese speakers of Mid-West dialect and the gender difference in average mean nasalance score. Nasalance scores were obtained using a nasometer model 6200. The sample stimulus "Kitsutsuki passage," constructed of four sentences containing no Japanese nasal sounds, was used three times by each subject. One hundred normal adult speakers (50 women and 50 men) of Japanese served as subjects. The subjects ranged in age from 19 to 35 years of age (24.0 +/- 3.2). A mean nasalance score as well as an overall average nasalance value across speakers was calculated for each subject. The average mean nasalance scores between men and women were compared. The average mean nasalance score for the normal Japanese speakers was 9.1% (+/- 3.9). There was no statistically significant sex difference (p < .01). Average mean scores of 9.8% (+/- 3.5) and 8.3% (+/- 4.0) were obtained for the female and male speakers, respectively. The results provide important information concerning criteria to evaluate hypernasal speech due to velopharyngeal inadequacy of Japanese speakers with cleft palate using the nasometer.

This study investigated the effects of training in/r/-/l/ perceptual identification on /r/-/l/ production by adult Japanese speakers. Subjects were recorded producing English words that contrast /r/ and /l/ before and after participating in an extended period of /r/-/l/ identification training using a high-variability presentation format. All subjects showed significant perceptual learning as a result of the training program, and this perceptual learning generalized to novel items spoken by new talkers. Improvement in the Japanese trainees' /r/-/l/ spoken utterances as a consequence of perceptual training was evaluated using two separate tests with native English listeners. First, a direct comparison of the pretest and post-test tokens showed significant improvement in the perceived rating of /r/ and /l/ productions as a consequence of perceptual learning. Second, the post-test productions were more accurately identified by English listeners than the pretest productions in a two-alternative minimal-pair identification procedure. These results indicate that the knowledge gained during perceptual learning of /r/ and /l/ transferred to the production domain, and thus provides novel information regarding the relationship between speech perception and production.

Recent research on American English /r/ and /l/ has suggested that adult Japanese speakers are more sensitive to changes in F2 frequency than to changes in F3 frequency. In contrast, adult American English speakers seem more sensitive to changes in F3 frequency. To examine the developmental origins of these cue weightings, 7.5-month-old infants raised in monolingual English homes were tested. Following the head-turn conditioning procedure, infants were trained to turn toward a visual reinforcer whenever a continuously repeated background stimulus was changed to a test stimulus. In an initial conditioning phase, infants were trained to discriminate two synthetic /ra/ and /la/ stimuli that differed in both F2 and F3. In the following test phase, infants discriminated these two stimuli along with stimuli that differed from the background along only one of these dimensions. The results demonstrated that infants were more sensitive toF2 than to F3, suggesting that their cue weightings may better match those of Japanese adults.

In this paper tongue activity during Japanese speech production was examined. Of interest was the identification of potential neural control strategies and biomechanical contributions underlying speech production by evaluating, separately and in combination, kinematic and electromyographic (EMG) activity of the tongue at normal and fast speaking rates. Three normal adult Japanese speakers (three male) served as subjects for this investigation. Hooked-wire electrodes were placed in three tongue muscles; two extrinsic (genioglossus anterior [GGA] and genioglossus posterior [GGP]) and one intrinsic, and two facial muscles (orbicularis oris inferior [OOI] and depressor labii inferior [DLI]). The two-dimensional movement data were recorded electromagnetically on the midsagittal plane using an EMMA system [Perkell etal. (1992)]. Upper lip, lower lip, tongue tip, and tongue body movement were recorded simultaneously with the EMG data. Though a variety of speech tasks were recorded, the present report will focus on three syllable words, /poteto/, in a carrier sentence, /ii−desu/ at a normal speaking rate and a subject-determined fast rate. It was found that EMG and movement characteristics were maintained for both normal and fast rate. Although at a fast speaking rate, movement amplitude were reduced, EMG amplitude were either maintained or somewhat increased.