Masako Fujimoto

A study of data normalization measured by an electro-magnetic articulograph

We investigated the normalization of the data measured using an electro-magnetic articulograph (EMA). The data normalization was needed because the size of the articulator of each subject is different from the sex and/or body size. Moreover, tongue movement range depends upon the speaking styles, clear or unclear. Our experiments were as follows: tongue tip movements during articulation of non-native consonant clusters were measured. Speakers were 2 Japanese and 2 Germans. Speech samples were 4 nonsense words, bnaht, pnaht, gnaht, knaht. Tongue tip displacement D (mm) and moving time T (ms) between first and second consonant in consonant clusters were measured. Dx (X component of D) was normalized by the difference between maximum value of X (Xmax) and minimum value of X (Xmin) in each utterance, i.e. Dnx=Dx/(Xmax-Xmin). Also Dy (Y component of D) was normalized, i.e. Dny=Dy/(Ymax-Ymin). Hence, Dn (normalized D) was Dn=(Dnx2+Dny2)1/2. T was normalized by word length L (ms), i.e. Tn=T/L. Before the normali...

Difference of articulatory movement between native and non-native consonant clusters

We investigated the difference of articulatory movement between native and non-native consonant clusters. English has consonant clusters, but Japanese does not. Therefore, speakers chosen for comparison were native English and native Japanese speakers. Speech samples consisted of 4 words, “blat,” “bnat,” “plat,” “pnat.” In these words, /bl/ and /pl/ are English clusters, but /bn/ and /pn/ are not. We measured the movement of the tongue tip, the mandible and the lower lip by WAVE system (NDI corp.). There were remarkable differences in the mandible and the lower lip movement between native (/bl/, /pl/) and non-native (/bn/, /pn/) clusters in English speakers. Namely, with the non-native clusters the difference of the articulatory movement in the mandible and the lower lip of every utterance was quite large; however, in native clusters, the difference was quite small. For Japanese speakers it was large for all clusters. Thus, it was revealed that the articulatory movement of the mandible and the lower lip in non-native clusters was not stable in native English speakers, even though English has consonant clusters. (This study was supported by KAKENHI 15K02524, 17K02707.)

Timing patterns of voiceless and voiced singleton and geminate plosives of Yanagawa Japanese

The paper examines acoustic timing patterns of word-medial voiceless and voiced singleton and geminate plosives of Yanagawa Japanese, one of the Chikugo varieties of Japanese spoken in the center of Kyushu (Japan). Unlike standard Tokyo Japanese, Yanagawa Japanese is characterized by frequent gemination of any types of consonants including voiced obstruents (e.g., /kuzzoko/ [kuddzoko] “sole, the fish,” /miroɡɡe/ [miɾoɡɡe] “a shell fish”). Five Yanagawa Japanese speakers were recorded. Another five speakers of standard Tokyo Japanese were also recorded as a control group. The stimuli consisted of nonsense words with C1V1C(C)2V2 structure (e.g., /kak(k)a/, /kaɡ(ɡ)a/). The findings suggest that the whole word duration containing geminate consonants was longer in proportion to mora count difference those containing singleton consonants, confirming moraic timing at word level in Yanagawa Japanese. When C2 was a geminate (voiceless or voiced), it lengthened the preceding vowel (V1) and shortened the following one (V2) in both dialects. However, the magnitude of influence of geminates to adjacent vowels was dialect specific: V1 duration in Yanagawa was consistently longer than Tokyo when the following consonant was a geminate. The results of the current study point towards the timing differences in singletons and geminates across Japanese dialects.The paper examines acoustic timing patterns of word-medial voiceless and voiced singleton and geminate plosives of Yanagawa Japanese, one of the Chikugo varieties of Japanese spoken in the center of Kyushu (Japan). Unlike standard Tokyo Japanese, Yanagawa Japanese is characterized by frequent gemination of any types of consonants including voiced obstruents (e.g., /kuzzoko/ [kuddzoko] “sole, the fish,” /miroɡɡe/ [miɾoɡɡe] “a shell fish”). Five Yanagawa Japanese speakers were recorded. Another five speakers of standard Tokyo Japanese were also recorded as a control group. The stimuli consisted of nonsense words with C1V1C(C)2V2 structure (e.g., /kak(k)a/, /kaɡ(ɡ)a/). The findings suggest that the whole word duration containing geminate consonants was longer in proportion to mora count difference those containing singleton consonants, confirming moraic timing at word level in Yanagawa Japanese. When C2 was a geminate (voiceless or voiced), it lengthened the preceding vowel (V1) and shortened the following o...

Articulatory movement in consonant clusters: A contrastive study of Japanese and English

We investigated the articulation of consonant clusters with Japanese and English speakers using the WAVE system (NDI Corp.). Until now we measured the displacement of tongue tip only, but in this study we also measured the displacement of the mandible. The subjects were three Japanese and two English speakers. The speech samples were 4 words: blat, bnat, plat, pnat. All these second consonants, /l, n/ are articulated with tongue tip placed behind alveolar ridge. These words were embedded in a carrier sentence, “Say X.,” and these sentences were uttered 5 times each in random order. The articulation time from first consonants, /b/, /p/, to second consonants, /l/, /n/, were measured. Specifically, the time from the highest point of the mandible to that of the tongue tip was measured. Overall average time was 131.2 ms (Japanese) and 48.1 ms (English). Two-way ANOVA (Language vs. Cluster) showed a significant main effect in Language (p<0.0001). This result suggested that for English speakers, the first and se...

Oral/nasal airflow during Japanese stop consonants

Voiced obstruents have inherent susceptibility for devoicing due to the Aerodynamic Voicing Constraints (AVC), and the susceptibility is higher for geminate obstruents than singletons. As a way to investigate how Japanese speakers realize the contrast between the [ + /-voice] contrast in obstruents, we examined oral and nasal airflow patterns during intervocalic voiced and voiceless stops, in singletons and geminates. The results showed asymmetry between single and geminate stops in realization of the stop voicing contrast. Airflow pattern clearly differentiates voiced vs. voiceless contrast in singletons, but the airflow patterns are similar in geminates. Acoustic signals also shows the same asymmetry between the singletons and geminates. The observed convergence—clear voicing contrast in singletons vs. the lack of the contrast in geminates both in air flow and acoustic signals indicate neutralization of the voiced geminates into voiceless ones. Our results support the idea of phonetic bases in phonologi...