Formant Transitions As Effective Cues To
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FORMANT TRANSITIONS AS characteristic as a place cue has been EFFECTIVE CUES TO statistically tested with ANOVA and Tukey’s HSD. DIFFERENTIATE THE PLACES OF ARTICULATION The results confirm the previous findings OF BAN PA LA-U SGAW (Liberman, Delattre, Cooper and Gerstman 1 1954, Malécot 1956, Recasens 1983, KAREN NASALS Harding and Meyer, 2003) that transitions 2 provide better cues for differentiating place Karnthida Kerdpol of articulation for nasals. Furthermore, this study found that among the formant Abstract frequencies in a formant transition, the F2 transition provides the most effective cue to The Sgaw Karen dialect of Ban Pa La–u, identifying the places of nasal articulation, Amphoe Hua Hin, Thailand, has four i.e. /ɲ/ has the highest F2 frequency value at nasals: /m/, /n/, /ɲ/, and /ŋ/, that appear in the nasal–vowel juncture, followed by /n/, syllable–initial position. Review of the /ŋ/, and /m/, respectively. The relational relevant literature indicates that initial /ɲ/ pattern between F2–F3 transitional has been less studied acoustically due to the directions can also aid in differentiating lack of palatal nasals in the consonant nasal articulation places; however, the systems of most languages. Thus, this Sgaw pattern of transitional direction depends on Karen dialect is suitable for investigating the vocalic context. The F2–F3 transitional place of articulation of nasals. patterns among the places of articulation clearly differ in the /ɔ/ context. In the case of The acoustic characteristics examined include a following /a/, the F2–F3 transitional the duration, intensity, and frequencies of the patterns for /n/ and /ŋ/ are very similar and formants (resonances) of the nasal murmurs do not act as a place cue. Although the second as well as the frequencies of the formant nasal formant (NF2) evinces consistent transitions into the following vowels /a/ and relational patterns, differences among /m/, /n/, /ɔ/. The significance of each acoustic and /ɲ/ are not statistically significant, 1 implying their similarity. Likewise, neither This paper was presented at the RGJ Seminar intensity nor duration of nasal murmurs can Series LXXXII: Southeast Asian Linguistics be used as cues to differentiate place of organized by The Royal Golden Jubilee Ph.D. articulation for nasals. Program (RGJ), Thailand Research Fund and Research Institute for Languages and Cultures of 1. Introduction Asia, Mahidol University on August 5, 2011. I would like to express my gratitude to Dr. In the production of nasal sounds, the oral and Chutamanee Onsuwan who was the discussant of the nasal cavities are coupled by the lowering of the session for her valuable comments and suggestions. velum. As a result, the acoustic characteristics 2 Ph.D. Candidate, Department of Linguistics, of nasal sounds are more complex than those of Faculty of Arts, Chulalongkorn University purely oral sounds. In the case of nasal Downloaded from Brill.com10/02/2021 07:56:12AM via free access MANUSYA: Journal of Humanities Regular 15.2, 2012 consonants, there is an obstruction in the oral bilabial, alveolar, palatal, and velar, thus cavity, but the velum is lowered, allowing offering an excellent opportunity to examine air to flow through the nasal cavity. The the cross–linguistically rare nasal /ɲ/. nasal cavity acts as the main resonator, while the oral cavity acts as a side branch, According to Matisoff (2008), the Sgaw absorbing sound energy. According to Ohala Karen language belongs to the Karenic (1975), since the nasal cavity is fixed in branch of the Tibeto–Burman language shape and size, the nasal formants caused by family. In Thailand, Sgaw Karen people are resonance in the nasal cavity are similar for mostly found in the northern and western the various places of articulation. The first provinces. In this study, the Sgaw Karen nasal formant (NF1) is very low in dialect spoken at Ban Pa La–u, located in Hua frequency. Formants above the first nasal Hin District, Prachuap Khiri Khan Province, formant are low in energy. On the other has been examined. The population of Ban Pa hand, the antiformant corresponding to La–u numbers one thousand one hundred and sound energy being absorbed in the oral is made up of Sgaw, Pwo, and Thais. Most of cavity varies from one place to another. The the Karen people are Christian, although some shorter the oral tract is, the higher the are Buddhist. Their birth places vary; some antiformant frequency value becomes. The were born in the village, some in Myanmar antiformant can, then, serve to differentiate and some around the Myanmar–Thailand place of articulation for the various nasal border. My Sgaw Karen informants speak stops. both Thai and Sgaw. See the sound inventory of the Ban Pa La–u Sgaw Karen in Place contrast for nasals has been Table 1 and 2. acoustically and perceptually studied to find what the best cue to place of articulation is. To find nasal place cues, both nasal murmurs Some studies have found that nasal murmurs and formant transitions have been widely consisting of nasal formants and the examined. Some studies have examined data antiformant act as place cues. Others have from natural speech, while others have argued that transitions provide better cues. conducted experiments using synthetic speech. However, due to the limited number of The results of these previous studies suggest languages being examined, only three places that formant transitions provide better cues for of articulation have commonly been differentiating place of articulation; however, investigated, i.e., bilabial, alveolar, and nasal murmurs also play a place–contrastive velar. The database compiled by Maddieson role. The relational patterns among the nasal and Precoda (1984) reveals that the bilabial formants and antiformants of nasal murmurs nasals are found most frequently in world and the formant frequencies of formant languages, followed by velar, alveolar, and transitions reported in these various studies palatal, in descending order of frequency. have been fairly consistent. Study of palatal nasals has been rare. Fortunately, nasal sounds in the Sgaw Karen of Ban Pa La–u in Hua Hin District are articulated in four places of articulation, i.e., 22 Downloaded from Brill.com10/02/2021 07:56:12AM via free access Formant Transitions as Effective Cues Table 1 Sgaw Karen Consonant System Place bilabial alveolar palatal velar glottal Manner stop ph p b th t d ch c kh k ʔ nasal m n ɲ ŋ fricative s x ɣ h trill r approximant w l j Only /ʔ/ can occur in final position. Table 2 Sgaw Karen Vowel System Advancement front central back HeighttHeight high i ɨ u mid e ə o low ɛ a ɔ Two diphthongs, /ai/ and /au/, are found. There are four tones in Sgaw Karen: Tone 1 is a mid tone with the phonetic realization [33] in non–checked syllables. Tone 2 is a low tone with the phonetic realization [21̤] or [21] in non–checked syllables. Tone 3 is a high tone with the phonetic realization [44] in non–checked syllables. Tone 4 is a falling tone with the phonetic realization [452] in non–checked syllables. 23 Downloaded from Brill.com10/02/2021 07:56:12AM via free access MANUSYA: Journal of Humanities Regular 15.2, 2012 1.1 Nasal murmurs found that the murmurs of /m/ and /n/ were quite effective in allowing identification of Nasal murmurs have been found to be place of articulation, with /m/ receiving the potential cues in differentiating the places of highest correct score due to its having the articulation in some studies (Malécot 1956, lowest nasal formant and antiformant of all the Recasens 1983). Nasal murmurs occur nasal stops, and Ohala (1975) and Recasens during the closure phase of nasal stop (1983) have claimed that /ŋ/ is distinguishable production and consist of nasal formants from /n/ and /ɲ/ due to its higher NF1 value and (NF) and an antiformant (NZ). Nasal the lack of an antiformant in the middle of the formants arise from resonance in the nasal nasal spectrum. cavity, which functions as the main resonator. Ohala (1975) has argued that 1.2 Formant transitions nasal formants tend to be stable across different places of articulation due to the Formant transitions have been proven to be fixed size and volume of the nasal cavity. effective cues in distinguishing place of Ohala (1975), Recasens (1983), and Harding articulation for nasals, especially with and Meyer (2003) state that the first nasal respect to the second formant (F2). Formant formant (NF1) occurs at about 200–300 Hz transitions start from the release of the and has more energy than other nasal consonant and move toward the more–or– formants, which occur at higher frequencies. less steady state of the vowel. F2 has been Furthermore, the disappearance of energy at the focus of place cue studies since its certain frequencies is the result of energy transitional direction and frequency value at absorption in the oral cavity. According to the nasal–vowel juncture has proven to be a Ohala (1975), the antiformant frequency is cue in many acoustic–perceptual studies. inversely proportional to the length of the Studies on the contrastive role of transitions oral cavity. A longer oral cavity produces a have shown that transitions following nasal lower antiformant frequency. Comparisons initials differ by places: a rising transition of the nasal murmurs for different places of follows /m/; a flat or falling transition articulation have shown that the highest to depending on vowel type follows /n/ lowest frequency values for NF1 run from (Liberman et al. 1954, Recasens 1983) a /ŋ/ through /ɲ/ and /n/ to /m/. As for the falling (Liberman et al. 1954) or a slightly antiformant, /ŋ/ likewise has the highest rising, falling, or flat transition follows /ŋ/ frequency value, followed by /ɲ/, /n/, and and a falling transition follows /ɲ/ (Recasens /m/.