Articulation Place Of Consonants In Standard Chinese: Research Based On EPG

The tip of the tongue, the apex, raises up and contacts the alveolar ridge. Meanwhile, the two sides of the tongue dorsum curve upward and approach the upper teeth on both margins of the hard palate, leaving space between them for air flow to squeezes through as air pressure behind the point of obstruction accrues. All of a sudden, the apex leaves the alveolar ridge, the air flow accumulated in the oral cavity is released, and the gesture of the tongue changes into that of the next phone. So complicated is the description of the articulatory process of consonant 1 in standard Chinese (SC), but the real coordination of muscles in the vocal tract during the production of a consonant is even more delicate. The articulatory processes of consonants and their variation in coarticulation pose as one of the most difficult phonetic phenomena to explore in experimental phonetic research of mandarin. The present research, applying quantitative and descriptive analyses, aims at (1) inducing articulation places of 17 consonants in SC and (2) describing their variation patterns in coarticulation with adjacent segments through changes in lingual-palatal contact. Consonants in the analysis include d, t, n, 1, z, c, s, zh, ch, sh, r, j, q, x, g, k, and the nasal final n(N).The articulation place is one of the two perspectives, concluded by traditional phonetic researchers through meticulous examination of pronunciation and perception of linguistic movements in the mouth, to analyze consonants. It distinguishes consonants whose obstruction in the vocal tract appears in different places on the upper jaw in contact with different parts of the tongue. With raw materials from "The Corpus of Dynamic Palatogram of Speech in Standard Chinese" established by Bao Huaiqiao, Zheng Yuling, and Chen Jiayou (Zheng Yuling, Zhu Siyu, 2001), a database of "Acoustic Parameters of Speech in Standard Chinese" is built up during the present research. Among all 70 parameters, T3, defined as the temporal point of the last frame of the maximum lingual-palatal contact area, is selected to represent the time of the target frame of the consonant. The lingual-palatal contact at T3 is analyzed with Contact Anteriority (CA) and Contact Centrality (CC) indices of Contact Index Method (CIM). Two dimensional charts with CA as horizontal axis and CC vertical axis are drawn to illustrate the anteriority of lingual-palatal contact and the height of the tongue dorsum.Results show that the alignment of consonants depending on the anteriority of lingual-palatal contact is in accordance with preceding experiments except for several minor differences. The apical consonants d, t, and n display the most anterior contact in dental and alveolar areas. Next are the preapical consonants z, c, and s whose lingual-palatal contact takes place in the alveolar area. The predorsal consonants j, q, and x come in the third place with the articulator mainly contacting the alveolar ridge and covering parts of areas before and after the alveolar ridge. The contact area of the apical lateral 1 covers alveolar and prepalatal areas due to its flexibility in the articulatory gesture. Following are the postapical consonants zh, ch, sh, and r whoseobstruction mainly forms between the apex and the alveolar ridge. The lingual-palatal contact of the radical consonants g and k is the least anterior in the oral cavity in which the radix approaches the boundary between the palate and the velum and forms the obstruction. The nasal final n (N) at the end of a syllable displays a much more flexible gesture than the initial n, because it does not require the obstruction between the articulator and the upper jaw as long as the nasal cavity keeps open. As a result, its lingual-palatal contact reflects much of the character of the initial phone in the next syllable.The sequence of consonants on the vertical level shares little in common with that on the horizontal level. According to the height of the tongue dorsum, predorsal j, q, and x and radical g and k are on the top of the list. Following are apical d, t, and n and postapical zh, ch, sh, and r. Next are preapical z, c, and s. The apical lateral 1 is on the bottom with the lowest height of the tongue dorsum.However, the above consonantal alignment of articulation places is not settled once for all. Intersegmental and even cross-segmental coarticulation takes place due to the anticipatory or carryover effect of articulatory gestures. Stemming from examination of consonants in different contexts including disyllables, sentences, poems, and narrations, variation in lingual-palatal contact of each consonant is illustrated in CA-CC chart and their coarticulation patterns are concluded and described accordingly.Firstly, consonants during whose production the apex or the lamina is involved as the articulator demonstrate a stronger degree of variation vertically than horizontally. The reason is that, while the apex or the lamina is engaged in constriction, the tongue dorsum has more freedom in its movement and is more likely to reserve some carryover features of the preceding phones or retain some anticipatory features of the ones that follow. Changes in lingual-palatal contact of apical d and t in coarticulation with adjacent phones best illustrate this point. On the contrary, consonants requiring the predorsum or the radix to be the articulator demonstrate a stronger degree of variation horizontally than vertically. Deviation from the target in lingual-palatal contact of radical g and k reveals this tendency, since the arch-shaped radix is highly restricted in its vertical movement.Secondly, the less restriction on the apex, the higher degree of horizontal variation, while the more freedom on the tongue dorsum, the greater change on the vertical level. One special case is the apical lateral 1 whose apex and dorsum are both highly flexible, and thus its variation in lingual-palatal contact covers a wide span of area on CA-CC chart.Concerning the extent of variation in lingual-palatal contact resulted from coarticulation effect, the 17 consonants ranging from the most flexible to the most resistant to changes are successively apical 1, the nasal final n(N), radical g and k,apical n, postapical zh, ch, sh, and r, preapical z, c, and s, apical d and t, and predorsal j, q, and x.Several limitations of the present research involve limitations of electropalatography (EPG), deficiencies of CC index, and the imperfection in the selection of the temporal point T3. Had the application of EPG and the electropseudopalate been more convenient and prevalent, sample recordings of more subjects could have been collected and analyzed to provide more possibilities of changes in lingual-palatal contact. CC index does not always reflect the height of the tongue dorsum, because it only calculates the number of contacted electrodes, i. e. lingual-palatal contact area, and does not take into consideration the lingual gesture that causes the contact. Similar places and areas of contact are highly likely to be induced by different even opposite dorsal gestures. Additionally, the place of lingual-palatal contact on the upper jaw at the temporal point of T3 which is directly related to the present research by no means represents in all cases the target place of articulation of the consonant. To select the adequate T3, both the lingual gesture and the position of contacted electrodes should be examined to ensure the reliability and representativeness of the selection.Careful observation of ample evidence of consonantal variation in coarticulation lends the researcher a keener insight into the recognition that the coordination of muscles along the vocal tract, such as the lingual gesture and the pharyngeal configuration, is the decisive factor in controlling the quality of consonants. Articulation place is the result of such delicate interaction and invites further experiments and discussions about more fundamental issues such as the influence of changes in the configuration of the vocal tract on the quality of overtly produced speech.