This study compares the rhythms of 16 Meiji Shoka (songs for school music classes) to their original English versions using the normalized Pairwise Variability Index (nPVI), which represents the rhythmic characteristics of languages. I assumed that any mismatch in nPVI values could be attributed to the rhythmic characteristics of the translated texts. Previous research indicated that English exhibits higher nPVI values than Japanese. The hypothesis proposed that the nPVI values of the originals would exceed those of the Japanese versions when discrepancies occur. The findings supported this, with one notable exception, for which an explanation is provided.

Facial landmarks are specific points on the face, such as the contours of the eyes and lips. Movements of these landmarks are closely related to the articulatory movements and acoustic features of speech, providing useful information for speech research. Recent advances in image processing technology have made it possible to easily identify the positions of these facial landmarks on facial images using public domain machine learning libraries. This paper reviews speech research using the facial landmarks and describes the process of extracting facial landmark coordinates from facial images with tools that can be used on web browsers.

This study investigated the articulation of the Korean liquid in initial positions using real-time MRI. Two female participants, both native speakers of Standard Korean, were recorded. Fifteen monosyllabic test words were generated twice. The investigation focused on the place of articulation and the manner of articulation, specifically the direction of tongue tip movement, the duration of tongue tip contact on the anterior palate, the distance between the anterior tongue and the hard palate, and the distance between the tongue root and the pharynx. This study revealed that each speaker exhibited distinct articulation patterns in producing the word-initial Korean liquid. Despite significant between-speaker variation, a common characteristic was that the closure duration of the Korean liquid was not brief. Therefore, the IPA representation of the word-initial Korean liquid is considered to correspond to [l] (voiced alveolar lateral approximant) for Speaker 1 and [ɭ] (voiced postalveolar retroflex lateral approximant) for Speaker 2, rather than [ɾ] or [ɽ]. Unlike English, where “L” and “R” create a contrast, Korean liquid has only a single liquid phoneme. It is hypothesized that the Korean liquid may occupy a larger articulatory and acoustic space, allowing for greater variation. Additionally, consistent tongue body raising motion (palatalization) was observed in both speakers, while there was no clear trend in tongue root fronting. For future studies on the investigation of the Korean liquid, various factors such as word position, age, region, gender, scene, and speech rate should be considered.

This paper investigates the articulatory coordination for consonantal sequences called nomu etc. in Noh Japanese theatrical performance, which is an orally-passed-down pronunciation maneuver of Sino-Japanese coda consonant -t released with a nasal plosion (e.g., [matn̩dai]). We conducted real-time MRI analysis for nine utai phrases of Noh by two professional performers. The results find that the oral articulation (tongue tip closure, TT) substantially precedes the nasal articulation (velic aperture, VEL). The acoustic analysis of the same phrases reveals a strong positive correlation of the duration between the oral (non-nasal) and nasal closure intervals, suggesting a constant timing relation between the two articulatory gestures. The two sets of results exhibit a sharp contrast with the coordination patterns found for onset (synchrony) and coda (sequential, with VEL preceding TT) in the preceding studies, underpinning an exceptional phonological status of nasal plosion of being a syllable coda and a syllabic consonant simultaneously.

This article outlines a quantitative, between-group comparison of tongue shapes using ultrasound tongue imaging, one of the vocal tract imaging techniques widely used in articulatory phonetics research. This article first provides a brief overview of ultrasound tongue imaging, followed by a description of a cross-speaker normalisation method based on bite plane rotation. It then outlines ultrasound data recording and analysis workflow with a case study illustrating data analysis using Principal Component Analysis (PCA). This paper demonstrates that the bite plane rotation, coupled with statistical normalisation methods, allows for a reliable tongue-shape comparison by establishing a common coordinate system across speakers.

This study examined the acoustic features and perceptual patterns by native and non-native speakers, and articulatory movements of vowel sequences in Japanese produced by Chinese learners (N1 holders). The participants were 19 Chinese learners and 7 native speakers of Japanese, all of whom were asked to pronounce nonsense words containing vowel sequences (e.g., /saesae/). During these pronunciations, the movements of the tongue were simultaneously recorded using ultrasound imaging. The native Japanese speakers revealed different formant distributions for each vowel. However, for the Chinese learners, there was a notable acoustic overlap in the second vowel of vowel sequences. In particular, the similarity in the tongue shapes between the vowels /ai/ and /ae/, as well as /au/ and /ao/, was observed. These findings indicate a strong influence of the native language, and even among advanced learners, reduced acoustic and articulatory properties of the second vowel in vowel sequences was confirmed.

This study investigated the voicing implementation of Japanese intervocalic stops using ultrasound and acoustic analysis. Acoustic analysis revealed that Japanese voiced stops exhibited a high voicing ratio during closure and a relatively short release burst interval, along with a high occurrence rate of consonant weakening. Japanese voiceless stops showed partial voicing during closure due to passive voicing from the preceding vowel. Articulatory analysis indicated that the tongue position at the maximal constriction was higher for voiceless stops than for voiced stops. Active sustainment of voicing was observed for voiced stops, and consonant weakening may also contribute to the sustainment.

This study investigates the tongue contours during the production of the vowel /a/ preceding geminate and singleton /t/ in Japanese. We report acoustic and articulatory results from a production experiment using ultrasound imaging. Our results generally support the previous literature predicting a relationship between pre-geminate vowel duration and extreme formant values, as well as more extreme articulatory gestures. We also observed interspeaker variability, some speakers not behaving as expected. Our results suggest the potential role of gestural timing and the need to consider the gestural coordination between the pre-geminate vowel and the surrounding segments.

This explanatory article presents experimental examples of voice quality analysis using Electroglottography. Emotional and attitudinal speech by Japanese native speakers and Chinese learners of L2 Japanese were recorded, and open quotient was extracted and compared. The results showed that vocal fold vibration patterns differed by the speaker’s native language, and Chinese native speakers tended to vocalize with tense vocal folds more often. The results also suggest that Chinese native speakers retain features of Chinese paralinguistic expression. Based on above results, we propose that EGG could be used to present voice quality information when devising instructional methods for Japanese language education.

Japanese is recognized as a mora-timed language. Although little is known about the physiological mechanism of special morae, recent studies have elucidated the physiological properties of special morae, highlighting differences in articulatory movement compared to regular morae. In order to clarify how the articulatory movements of special morae were organized during the developmental course, this paper examined the production of long vowels in Japanese children, focusing on lip movements. The results revealed that, contrary to adults, children did not exhibit a greater degree of lip opening for long vowels. This suggests a potential influence of underdeveloped articulatory movements in language development.