音声研究 第 22 巻第 2 号 Journal of the Phonetic Society 2018（平成 30）年 8 月 of Japan, Vol. 22 No. 2 131–140 頁 August 2018, pp. 131–140 特 集 ノート Voice Onset Time of Word-Initial Stops and Affricates in Khalkha Mongolian Naoki UETA* モンゴル語ハルハ方言の語頭破裂音・破擦音のVOT SUMMARY: Khalkha Mongolian has two types of obstruents, which are transliterated as〈 b, d, g, dz, ǰ〉 and〈 p, t, k, ts, č〉, respectively; however, it is not clear whether the feature distinguishing them is voicing or aspiration. This production study examines the distribution of the VOT values between the two series of word-initial obstruents in Khalkha Mongo- lian. The data show that VOTs of〈 b, d, g, dz, ǰ〉 generally show positive values and that there is no phonetic ground to view /g/ and /ɢ/ as voiced consonants, although they are phonologically regarded as voiced. Key words: Khalkha Mongolian, voice onset time, obstruent, place of articulation, speech production 1. Introduction ranges: one from about −125 ms to −75 ms (voiced unaspirated stop), one from 0 to ＋25 ms (voiceless un- In Khalkha Mongolian (henceforth just Mongolian), aspirated stop), and one from about ＋60 ms to ＋100 ms widely spoken in Mongolia and also called Standard (voiceless aspirated stop). Mongolian, there are two contrastive series of stops and It is well known that the features of voicing and as- affricates (obstruents)1). In Cyrillic letters2) and their piration for syllable-initial stops can be specified quite common transliterations, the two series of obstruents well only by VOT, and a number of cross-linguistic are rendered as shown in Table 1 (Sanders and Bat- studies have been conducted to show the validity of Ireedüi 1999, pp. 3–4, Shiotani and Prevjav 2001, p. 2, VOT for doing so (Shimizu 1996, Cho and Ladefoged Yamakoshi 2012, p. 19). 1999, Takada 2011; among others). However, few The alphabetical transcription seems to imply that reports are available on VOT values of Mongolian this contrast is one of voicing. However, it is still not obstruents. clear precisely what phonetic or acoustic features dis- My aim is to examine the distribution of VOT values tinguish these two types of sounds. of each obstruent in Mongolian with a speech produc- In this study, I focus on voice onset time (VOT) of tion experiment. In the following section, I provide Mongolian word-initial obstruents. VOT, which is an an overview of previous studies and point out some acoustic feature proposed by Lisker and Abramson remaining problems. Section 3 describes the current (1964), is the time interval between the articulatory production experiment. In section 4, I present the re- release of the stop and the onset of vocal fold vibration. sults of the experiment and show that (i) VOT of〈 b, VOT takes a positive value if the vocal fold vibration d, g, dz, ǰ〉 generally takes positive values, (ii) VOT starts after the articulatory release and, conversely, of velar and uvular stops is longer than that of bilabial takes a negative value if voicing precedes the release. and dental stops, (iii) there is no phonetic ground to Lisker and Abramson (1964) examine 11 languages view /g/ and /ɢ/ as voiced consonants, although they and show that the stop categories fall into three VOT are phonologically regarded as voiced, and (iv) young Mongolian speakers distinguish〈 k〉 [kh] from〈 g〉 [q] Table 1 Cyrillic letters for Mongolian obstruents and phonetically, though some previous studies state that their transliterations. 〈k〉 is replaced by [x, ɡ, ɢ]. Section 5 is the conclusion of this paper. п〈 p〉 т〈 t〉 ц〈 ts〉 ч〈 ch〉 к〈 k〉 б〈 b〉 д〈 d〉 з〈 z〉 ж〈 j〉 г〈 g〉 * Graduate School of Language and Culture, Osaka University（大阪大学言語文化研究科） — 131 — 特集「有声性の対立に関する音声と音韻」 Table 2 Mongolian stops and affricates (Svantesson and Karlsson 2012, p. 453)3). Labial Dental Post-alveolar Velar Uvular Aspirated stop ph th Unaspirated stop p t Voiced stop g ɢ Aspirated affricate ʦh ʧh Unaspirated affricate ʦ ʧ Table 3 Mean VOT duration (in ms) (Svantesson and 2. Previous Studies of Mongolian Obstruents Karlsson 2012, p. 456). As shown in section 1, the two contrastive series VOT of obstruents in Mongolian are usually rendered with Speaker h symbols for voiceless and voiced consonants in Cyrillic /t -/ /t-/ p-values letters and their transliterations. In phonological analy- BB 57 22 p＜.05 ses, the terms strong - weak (čanga - sul in Mongolian), DD 58 11 p＜.001 fortis - lenis, and tense - lax are traditionally used for XB 40 23 p＜.01 these two series of obstruents, and many researchers /ʦh-/ /ʦ-/ have described the basic phonetic characteristics of each sound (Stuart and Haltod 1957, Luvsanvandan BB 102 47 p＜.01 1964, Poppe 1970, Tsoloo 1976, Möömöö 1979, for DD 88 57 p＜.01 XB 76 49 p≥.05 example). However, there is little consensus on which distinctive feature distinguishes these two series. For /ʧh-/ /ʧ-/ example, Poppe (1970) and Janhunen (2012) found that BB 85 58 p＜.05 Mongolian “tense” obstruents are voiceless aspirated DD 108 60 p≥.05 consonants and “lax” obstruents are voiceless unaspi- XB 70 49 p≥.05 rated consonants, while Tsoloo (1976) and Sambuudorj (2012) regard “strong” and “weak” obstruents to be voiceless and voiced, respectively (for more details, see about −20 ms to about ＋20 ms. In Japanese, accord- Svantesson et al. 2005, pp. 220–221). ing to Takada (2011, pp. 70–71), VOT of word-initial Recently, Svantesson et al. (2005), Karlsson and voiced stops is distributed from −320 ms to ＋74 ms Svantesson (2011, 2012), and Svantesson and Karls- and there are two peaks of distribution; one around son (2012) have claimed that the distinctive feature −80 to −60 ms and the other around 0 to ＋10 ms. In which distinguishes these two series of obstruents in Mongolian, however, it is not clear whether VOT of Mongolian is aspiration: post-aspiration word-initially unaspirated (or voiced) obstruents can take negative and pre-aspiration in the other positions. Table 2 shows values or whether it always takes positive values. the phonological system for the stops and affricates The second, and the more crucial, problem is that proposed in Svantesson and Karlsson (2012). the data are limited to dental stops, dental affricates, Svantesson and Karlsson (2012) presented some and postalveolar affricates. In other words, labial, ve- acoustic data, including on VOT; according to their lar, and uvular stops were not studied by Svantesson measurements, mean VOT values for word-initial /th–t/, and Karlsson (2012). This limitation may have been /ʦh–ʦ/ and /ʧh–ʧ/ are those shown in Table 3. unavoidable because the studies in question have tried The acoustic data seem to support their interpreta- to examine acoustic characteristics of obstruents in all tions in Table 2. However, there are some remaining positions, and only dental stops, dental affricates, and issues. postalveolar affricates frequently occur in all positions First, the distribution of VOT values is not clear, in Mongolian. It is known, however, that VOT gener- since Svantesson and Karlsson report only mean val- ally varies among places of articulation. For example, ues. It is well known that VOT of voiced obstruents Kent and Read (1992, p. 114) show that bilabials have can take both negative and positive values in some the shortest VOTs and velars have the longest. Cho languages; for example, Kent and Read (1992, p. 108) and Ladefoged (1999) analyze the VOT values in 18 show that VOT of voiced stops in English ranges from languages and report that “velar stops have the lon- — 132 — Voice Onset Time of Word-Initial Stops and Affricates in Khalkha Mongolian gest VOTs in all of the 13 languages that do not have is the case and the VOT range of this sound differs from contrasts between velar and uvular stops; and in the that of〈 g〉, it follows that there is a phonetic contrast remaining five languages either velars or uvulars have between〈 k〉 and〈 g〉. In addition, if〈 k〉 is seldom re- the longest VOT” (p. 218). Taking these facts into con- placed by the native sounds [x, ɡ, ɢ], it seems that there sideration, it is necessary to examine the VOT values of is room for discussion on whether this sound should be all kinds of obstruents in Mongolian in order to explore acknowledged as a phoneme /k/, even if it occurs only the phonological nature of this contrast. in loan-words, that is, not even in onomatopoeia. In particular, the acoustic data for velar and uvular To summarize, the following questions still remain stops need to be analyzed. Although Svantesson et al. open regarding “the voicing contrast” in Mongolian: (2005, p. 12) state that Mongolian velar and uvular stops are often voiced [ɡ, ɢ] and transcribe them as (2) a. What are the distributions of the VOT values voiced stops /g, ɢ/, they present no acoustic evidence of each obstruent? for this interpretation4). In addition, as shown in Table b. Do the VOT values vary substantially among 2, they claim that the velar and uvular stops only have places of articulation? voiced series, that is, there is no phonemic voicing con- c. Can the observation that the velar and uvular trast in velar and uvular positions. However, the letter stops are phonetically voiced be confirmed к〈 k〉 is present in the orthography, as shown in Table by actual VOT data? 1, and к〈 k〉 occurs in loan-words. Svantesson et al. d. Is it true that the borrowed〈 k〉 is pronounced (2005) state with respect to the pronunciation of〈 k〉 in either as [x, ɢ, ɡ] (i.e., substitution with the loan-words as follows: native phones) or [k] (like Russian /k/)? (1) a.