Tonetics

As indicated in various tonological models, tonal contrasts are largely characterised with the perceptual dimension of pitch corresponding to the acoustic dimension of fundamental frequency (F0), reflecting the rate of vibration of vocal cords (Rose, 1982, 1993). Thus, the differences in tones are often assumed to be a matter of differences in pitch or F0 (Kong, 1987). Nevertheless, increasingly, studies of unrelated tonal languages have been revealing that, beyond the differences in pitch/F0, tonal contrasts often involve systematic interaction with other phonetic parameters, for example, duration, aspiration, phonation, vowel quality, and manner of initial consonants (e.g., Schuh, 1978; Rose, 1982; 1988; Whalen & Levitt, 1995; Fox, 2000; Connell, 2002; Faytak & Yu, 2011; Zhu, 2012). This section reviews how tonal pitch/F0 interacts with other phonetic parameters to create tonal realisations and distinctions.

1.4.1. Pitch/F0 and vowel quality

Research on the interaction between pitch/F0 and vowels can be categorised into two areas. One concerns the intrinsic correlation between pitch/F0 and vowel height (Hombert, 1978; Connell, 2002; Fox, 2000; Whalen & Levitt, 1995; Hoole & Hu, 2004) while the other considers the occurrence restriction of vowels with respect to different tones (Yip, 1980, 2002; Ping, 1995; Chan, 1985; Myers & Tsay, 2003; Donohue, 2007, 2013; Mortensen, 2013).

First, it has been attested cross linguistically that high vowels tend to have a higher fundamental frequency than do low vowels (Connell, 2002; Fox, 2000; Whalen & Levitt, 1995). For instance, Whalen & Levitt (1995) conducted a survey on 31 languages from 11 language families to investigate the intrinsic interaction between F0 and vowel quality. Results justified the general assumption of a positive correlation between vowel height and F0 height, and also indicated the intrinsic F0 varies as a function of vowel height and having no significant correlation with the dimension of vowel backness.

Second, vowel quality has been reported undergoing alternation in accordance with specific tonal environments, for example, in the Mang dialect of Shuijingping (Mortensen, 2013) and Fuzhou (Yip, 1980, 2002; Ping, 1995; Chan, 1985; Myers & Tsay, 2003; Donohue, 2007; 2013). Specifically, a vowel-raising process was found in Fuzhou with respect to the higher pitched tones, as shown in Table 1-5 (Myers & Tsay, 2003, p. 119).

Table 1-5. Vowel alternations with respect to tones in Fuzhou

Tone Vowel alternation

LM, LML æ ai au ay ei ou œy ieu uoi

1.4.2.Pitch/F0 and duration

The correlation between vowel duration and pitch has been studied cross-linguistically (e.g., Zee, 1978; Kong, 1987; Yu, 2010; Faytak & Yu, 2011). In general, vowels on low tones are found to have a longer duration than they are on high tones, and vowels on rising tones appear longer than on falling or level tones (Yu, 2010; Faytak & Yu, 2011). In other words, pitch/F0 height and duration are correlated negatively: The higher the pitch/F0, the shorter the duration; the lower the pitch/F0, the longer the duration.

Counter-examples are also found showing a positive association between pitch and duration, such as in Taiwanese (Zee, 1978; Kong, 1987), Cantonese (Faytak & Yu, 2011), and Yucatec Maya (Faytak & Yu, 2011). Specifically, the mid-level tone in Cantonese is observed longer than the mid-low level tone (Faytak & Yu, 2011).

1.4.3.Pitch/F0 and consonant

The intrinsic correlation between pitch/F0 and (prevocalic) consonants has been widely reported in the literature (e.g., Halle & Stevens, 1971; Hyman & Schuh, 1974; Hombert, 1976, 1978; Abramson & Erickson, 1978; Ohala, 1978; Rose; 1996; Thurgood, 2002; Yip, 1980, 1989, 2002; Xu & Xu, 2003; Lai & Jongman, 2005; Francis et al., 2006; Lai et al., 2009; Ladefoged & Disner, 2012). For example, Hyman & Schuh (1974, p. 110) proposed a phonetic hierarchy showing continuous consonant-induced perturbative effects ontonal pitch as shown in Figure 1-2.

Figure 1-2. Phonetic hierarchy of consonant-induced perturbative effects on tonal pitch/F0 realisation.

As indicated in this figure, the prevocalic voiced obstruents are treated to have a depressing effect on the pitch/F0 onset of following vowels while their voiceless counterparts can raise the onset (Hombert, 1978; Abramson & Erickson, 1978; Yip, 2002; Lai & Jongman, 2005). The voicing- induced perturbation effect on pitch/F0 generally has been considered a main motivator of tonal development in Chinese (Yip, 2002), Thai (Abramson & Erickson, 1978), Vietnamese (Thurgood, 2002), and many languages in Tibetan-Burman, Austronesian, and Hottentot languages in South Africa (Hombert, 1978, p. 79 and reference therein). Specifically, the concept of Yin and Yang register in Sinitic languages reflects the association between tonal pitch and voicing status of syllable onsets in historical times, and is still commonly used to classify spontaneous tones. In addition, aspiration (positive lag of voice onset timing) is generally considered to have a raising perturbation effect on the pitch/F0 of following vowels in languages regardless of whether they

are tonal or not (Hombert, 1976, 1978; Yip, 2002; Xu & Xu, 2003; Lai & Jongman, 2005; Francis et al., 2006; Lai et al., 2009). For example, Lai et al. (2009) found the F0 is statistically significantly higher in the aspirated than in the unaspirated environment in Taiwanese.

Nevertheless, some languages are reported as showing conflicting results (Hombert, 1976, 1978). For example, the aspiration-induced perturbation effect on the F0 onset is found not systematic in American English and French (Hombert, 1976), and Hindi has a higher F0 after voiceless, unaspirated obstruents rather than after aspirated obstruents (Hombert, 1978).

1.4.4. Pitch/F0 and phonation

The function of phonation in tonal systems has received substantial attention (e.g., Ladefoged, 1971; Laver, 1980; Huffman, 1987; Andruski & Ratliff, 2000; Gordon & Ladefoged, 2001; Pan, 2005; Garellek & Keating, 2011; Esposito, 2010, 2012; DiCanio, 2009, 2012; Zhu, 2012; Kuang, 2013; Mortensen, 2013). Ladefoged (1971) proposed a continuum of phonation types with respect to the openness of glottal status, as shown in Figure 1-3 (Gordon & Ladefoged, 2001, p. 1).

Figure 1-3. Continuum of phonation types.

Cross-linguistic studies have revealed three different functions that phonation generally plays in tonal languages (Andruski & Ratliff, 2000; Gordon & Ladefoged, 2001; Kuang, 2013; Garellek & Keating, 2011; DiCanio, 2012; Zhu, 2012; Mortensen, 2013).

First, non-modal phonation occurs as an allophonic variant of modal phonation, depending on a specific tone, for example, in White Hmong (Esposito, 2012), White and Blue Hmong (Huffman, 1987), Green Hmong (Andruski & Ratliff, 2000), and Itunyoso Trique (DiCanio, 2012). For example, each Burmese tone is characterised by a particular type of phonation, including a low, modal-voiced tone; a high, breathy tone; a high, creaky tone; and a very high, tense-voiced tone (Mortensen, 2013, p. 204).

Second, non-modal phonation intersects independently with the tonal system, possibly multiplying the number of tonal contrasts (Andruski & Ratliff, 2000; Gordon & Ladefoged, 2001; DiCanio, 2009; Garellek & Keating, 2011; Kuang, 2013; Mortensen, 2013). For example, San Felipe Jalapa de Di_{́az (Jalapa) Mazatec contrasts three phonation types (breathy, modal, and} laryngealised) and three level tones (low, mid, and high) independently (Garellek & Keating, 2011). Another possibility is that non-modal phonation is occasionally associated with a certain tone among some speakers and for some occasions; for example, the third tone in Mandarin is produced occasionally with creaky phonation (Kuang, 2013).

1.4.5.Pitch/F0 and syllable coda

The presence of syllable obstruent codas is generally considered able to constrain the number of tonal contrasts and determine which tone should appear in many tonal languages in East and Southeast Asia (e.g., Benedict, 1948; Pike, 1948; Leiste, 1976; Gandour, 1978; Ballard, 1988; Chen, 2002; Zhang, 2007; Ratliff, 2015). For example, Hyman (2012, p. 191) summarised the limiting effect of obstruent codas on tonal contrasts in several Sino-Tibetan languages, as shown in Figure 1-4.

Figure 1-4. Limiting effect of obstruent codas on tonal contrasts in Sino-Tibetan languages.

As indicated in Figure 1-4, a full inventory of tonal contrasts is preserved in “smooth” syllables that end in sonorant codas while the number of tonal contrasts is reduced greatly in “stopped” syllables that end in obstruent codas at the underlying level (Hyman, 2012, p. 191). In addition, the tonal contrasts found in stopped syllables tend to be a subset of those shown in smooth syllables. Thus, tones appear asymmetrically distributed with respect to the syllable coda types. Nevertheless, how the asymmetry of tonal distribution can be accounted for formally can give in the literature. For example, the tonemic approach considers the stopped tones and smooth tones as two distinct categories (Sagart, 1998; Chen, 2000) while the allotonic approach treats the stopped tones as an allotonic subset of the smooth tones (Benedict, 1948; Hyman, 2012).

As discussed, the close interactions between tonal pitch and other phonetic parameters have been increasingly reported; however, it is not common to see empirical studies that have incorporated various segmental and suprasegmental parameters to investigate the nature of tonal realisations, especially in Sinitic languages. This thesis is devoted to advancing tonal studies by proposing a multidimensional framework to examine what tones are essentially realised across different linguistic contexts, and how various parameters interact to shape tonal distinctions.