Laryngeal contrasts in the Tai dialect of Cao B
`
˘
ang
Pittayawat Pittayaporn
Chulalongkorn University
Pittayawat.P@chula.ac.th
James Kirby
University of Edinburgh
j.kirby@ed.ac.uk
The Tai dialect spoken in Cao Bằng province, Vietnam, is at an intermediate stage
between tonal register split and the accompanying transphonologization of a voicing
contrast into a dual-register tone system. While the initial sonorants have completely lost
their historical voicing distinction and developed a six-way tonal contrast, the obstruent
series still preserves the original voicing contrast, leaving the tonal split incomplete. This
paper presents the first acoustic study of tones and onsets in Cao Bằng Tai. Although
f0, VOT, and voice quality were all found to play a role in the system of laryngeal
contrasts, the three speakers considered varied in terms of the patterns of acoustic cues
used to distinguish between onset types, particularly the breathy voiced onset /b/. From the
diachronic perspective, our findings may help to explain why the reflex of modal pre-voiced
stops (
∗
b) can be either aspirated or unaspirated voiceless stops.
1 Introduction
In languages where tonal contrasts are already established, it is widely agreed that subsequent
loss of voicing contrasts can trigger a binary or ternary tone split that doubles or triples the
number of tones (Haudricourt
1954, 1961, 1972). While the precise details vary, a common
scenario is illustrated by the development of the four-tone system of Sgaw Karen (
Figure 1).
Historically, this language had a system of two tones, high (A) and falling (B). These two tones
later split into four under the influence of the laryngeal specification of the initial consonant,
with modal voiced stops and voiced sonorants conditioning a low register and other onsets
conditioning a high register (Haudricourt
1972).
Voice quality has long been thought to play an important role in mediating this process
of tonal split. Breathiness, in particular, is thought to arise as a redundant phonetic cue to
onset voicing, with its subsequent loss hypothesized to mediate the emergence of new tonal
categories in many languages (Haudricourt
1954; Pulleyblank 1971, 1978; Kingston 2001;
Thurgood 2002). In the Karen scenario, for example, this would mean that the proto-voiced
stops (
∗
b,
∗
d,
∗
g) first passed through a breathy stage prior to tone split and subsequent
devoicing. However, it is unclear whether such a voice quality stage is a strictly necessary
condition for a tone split. In addition, it remains a puzzle precisely how the system of laryngeal
contrasts is restructured in response to tonal register split. This lack of understanding is due in
Journal of the International Phonetic Association (2017) 47/1
C
International Phonetic Association
doi:
10.1017/S0025100316000293 First published online 13 September 2016
https://doi.org/10.1017/S0025100316000293 Published online by Cambridge University Press
66 Pittayawat Pittayaporn & James Kirby
Figure 1 Binary tone split in Sgaw Karen, adapted from Haudricourt (1972: 62).
no small part to the fact that languages that have doubled their existing tonal inventory without
subsequent loss of the original laryngeal distinction are extremely rare, the best-known case
being Shanghai Chinese (Norman
1988;Chen2008: 199–200). Such ‘intermediate’ languages
are nonetheless crucial to our understanding of tonogenesis, tonal register split, and related
phenomena.
The Tai dialect of Cao Bằng (CBT), spoken in a remote and mountainous region of
northeastern Vietnam, is that rare specimen of a tonal language caught in the middle of
a tone split. In most Tai languages, the three-tone system of Proto-Tai split into six tones
following the collapse of the voicing contrast. What makes CBT special is that it has been
reported to retain a four-way laryngeal contrast between voiceless unaspirated, voiceless
aspirated, modal voiced, and breathy voiced obstruents that has been lost in the majority of
Tai languages (Haudricourt
1949, 1961, 1972, 1979;Ho
`
ang 1997; Pittayaporn 2009). If this
four-way contrast is in fact preserved, an acoustic study could provide important new data on
the role of voice quality in the evolution of tone systems.
In this paper, we present the first instrumental phonetic analysis of CBT, with the aim of
better understanding how its four-way laryngeal contrast is signaled phonetically. In particular,
we examine the roles of fundamental frequency (f0), voice onset time (VOT), and voice
quality in cueing the different categories, with a special focus on the role that breathiness
plays in the phonological system. We find that different speakers use different patterns of
acoustic cues to signal the same phonological categories. Crucially, it appears that breathiness
may either be tightly linked to pre-voicing or decoupled from it. We then discuss how
this variation might reflect the divergent outcomes of the tonal register split in the Tai
family.
2 Background: Voice quality and tonal register splits
Transphonologization of laryngeal contrasts into lexical tones is a common phenomenon in
many parts of the world, especially in China and Mainland Southeast Asia. The simplest
scenario involves languages that are non-tonal. A well-known example is Northern Kammu,
in which the loss of onset voicing yielded a two-way tonal contrast (Svantesson & House
2006). Words that used to have voiceless onsets now occur with a high lexical tone, while
those with voiced onsets now occur with a low tone. However, this transformation did not
come directly from onset voicing itself, but appears to have been crucially mediated by voice
https://doi.org/10.1017/S0025100316000293 Published online by Cambridge University Press
Laryngeal contrasts in the Tai dialect of Cao B
`
˘
ang
67
Figure 2 Tonal register split and neutralization of laryngeal contrast (from Pittayaporn 2009: 248).
quality differences that first arise as redundant cues to laryngeal contrasts (Premsrirat
2001,
Svantesson & House
2006).
A more complex scenario is when laryngeal contrasts induce tonal splits in languages that
already have lexical tones. The best-known case may be that of Vietnamese. This language
first developed three contrastive tones from original contrasts in syllable-final consonants
(Maspero
1912, Haudricourt 1954, Thurgood 2002, Ferlus 2004); subsequently, each of the
three tones split into two under the influence of the syllable-initial voicing contrast. The
six pitch patterns only became fully contrastive tones when the original voicing contrast
in the onsets was lost. Similar to the onset-based tonogenesis, the tonal register split
has been proposed to include an intermediate stage during which voice quality plays an
important role in the contrast system of the language (Pulleyblank
1970, 1971; Thurgood
2002).
This type of tonal register split has occurred in virtually all Tai, Chinese, and Hmong-
Mien varieties as well as individual languages in the other major families of Southeast Asia
(Haudricourt
1961, 1972; Gedney 1972; Matisoff 1973, 2001, 2003;Li1977; Thurgood
1999; Thurgood & Thurgood 2005; Pittayaporn 2009: 238–285; Ratliff 2010). Pittayaporn
(
2009: 248) schematizes the interrelated processes of tonal register split and neutralization
of laryngeal contrasts in the onset in four major stages, as illustrated in
Figure 2.Inthis
framework, Proto-Tai is reconstructed as being in Stage I (Haudricourt
1956,Li1977,
Pittayaporn
2009), while the grand majority of modern Tai varieties have reached Stage
IV, or have undergone additional tonal splits and mergers. CBT represents a language at
Stage III, one that has neutralized the voicing contrast in initial sonorants but has retained
it in initial obstruents, along with voice quality differences most other Tai languages have
lost. As a result, while the modern language has six lexical tones, the tones in CBT are
fully contrastive only on sonorant-initial syllables. For obstruent-initial syllables, three of
the six tones can occur only with voiced fricatives and breathy voiced stops, with the other
three being restricted to modal pre-voiced, voiceless aspirated, and voiceless unaspirated
stops.
One issue that is often left undiscussed in the literature on tonal register split is the fate of
breathiness after tonal split has occurred. Previous studies have revealed at least three types of
https://doi.org/10.1017/S0025100316000293 Published online by Cambridge University Press
68 Pittayawat Pittayaporn & James Kirby
outcomes. First, breathiness may be reanalyzed as a property of a subset of tones. In this type
of systems, the tones in syllables that originally had voiced onsets are predictably breathy.
Shanghai Chinese (Norman
1988: 199–200), Sach/Ruc (Ferlus 1998) and Tamang (Mazaudon
& Michaud
2008) are examples of languages of this type. Second, breathiness can be
completely lost. This seems to be the default outcome, as in most languages the original voiced
stops turn into voiceless unaspirated stops. Examples include Tsat (Thurgood & Thurgood
2005), Khuen (Owen 2012), Shan (Edmondson 1997, Edmondson 2008) and most other Tai
varieties (Chamberlain
1975). In the last and least understood type of outcomes, breathiness
is reanalyzed as aspiration, i.e. as a property of the onset. Pulleyblank (
1978) explains the
fact that Middle Chinese voiced onsets are reflected as voiceless aspirated in Mandarin when
occurring with level tone by postulating that the breathiness of the onset was reanalyzed
as aspiration, i.e. pʱ V > pʰ V. Comparing to the complete loss of breathiness, this type of
development occurs in a smaller number of languages. Some examples include Gan dialects
(Sagart
1984, 1992), Central Thai (Abramson 1962, Brown 1965, Abramson & Erickson
1978), Lao (Brown 1965, Ostananda 1997), and a few other Tai varieties (Chamberlain
1975). We are hopeful that additional synchronic studies of languages of these types will help
us to understand the role and fate of voice quality in the emergence of tone systems more
generally.
3 Tones and onsets in CBT
The Tai language of Cao Bằng is a member of the Tai branch of the Kra-Dai language family.
The specific variety investigated in the current study is spoken by ethnic T
`
ay in Tr
`
ung Kh
´
anh
District, Cao Bằng Province, in the extreme northeast of Vietnam (
Figure 3). As described by
Ho
`
ang (
1997) and Pittayaporn (2009), it is very similar to varieties spoken in other districts
of Cao Bằng reported by Haudricourt (
1960) and Ross (1996), and shows a strong overall
resemblance to the dialect spoken just across the border in Daxin County in Guangxi Zhuang
Autonomous Region as reported by Zhang et al. (
1999). Estimating from the total population
of the district, there are approximately 50,000 speakers of the Tr
`
ung Kh
´
anh variety of CBT
(Socialist Republic of Vietnam Government
2013).
Like all its Tai relatives, CBT features multiple laryngeal contrasts in the onset and a
sizeable inventory of level and contour tones.
Table 1 shows the consonant inventory of CBT,
including the four types of labial and alveolar onsets. The phonological analysis of CBT in this
study is based on the first author’s fieldwork carried out in 2008, which differs slightly from
the sketch by Ho
`
ang (
1997).
1
As shown in Table 1, voicing in CBT is contrastive for stops
and fricatives but not for nasals, liquids, or glides, which are always voiced. The distinction
among the voiceless aspirated /pʰ/, voiceless unaspirated /p/, modal voiced /b/, and breathy
voiced /b/ stops is clearly illustrated by the contrastive sets in example (1) below. Note that
the breathy voiced stops have different tones from the other three types of stops.
(1) Laryngeal contrasts in CBT obstruent onsets
/pʰaː
43
/ ‘to split’ /tʰɔːŋ
53
/ ‘waterfall’
/paː
43
/ ‘woods’ /tɔːŋ
53
/ ‘big leaf for wrapping’
/baː
43
/ ‘shoulder’ /dɔːŋ
53
/ ‘related by marriage’
/baː
33
/ ‘to mate’ /dɔːŋ
21
/ ‘copper, brass’
1
We analyze Ho
`
ang’s palatalized consonants as clusters, e.g. /p
j
-/ is treated as /pj-/. Our inventory also
lacks /f/ as the only word with the voiceless labial fricative cited in Ho
`
ang’s description is not attested in
our data.
https://doi.org/10.1017/S0025100316000293 Published online by Cambridge University Press
Laryngeal contrasts in the Tai dialect of Cao B
`
˘
ang
69
Figure 3 (Colour online) The location of Cao B
`
˘
ang province (red) in northern Vietnam. Administrative boundaries based on GADM
database version 2.7 (Global Administrative Area
2015).
It is important to note that what we transcribe as modal and breathy voiced stops are
transcribed as modal and pre-glottalized by Ho
`
ang (
1997), who analyzed the CBT phonemic
system based on his native-speaker intuition. Moreover, we transcribe Ho
`
ang’s /ɣ/ as a breathy-
voiced stop /
ɡ/. This modal-vs.-breathy analysis is supported by the acoustic results discussed
in
Section 5. One plausible explanation for the difference might in fact be a carry-over from
the transcription convention for Vietnamese: Ho
`
ang may have chosen /ɣ/ rather than /ɡ/to
transcribe this sound because the former is the only voiced velar sound in Vietnamese.
With respect to lexical tones, CBT makes a six-way contrast in terms of both pitch height
and pitch contour, illustrated by the contrastive set in
Table 2. The pitch value for each tone
given here is based on the description by Ho
`
ang (
1997).
2
These six tones can be divided into
2
Our tonal notation differs slightly from that used in Ho
`
ang (1997): our Tone 2 corresponds to his Tone
5 and vice versa, in order to highlight the association of tone and register. For clarity, we have used his
numerical tone values throughout (5 = high, 1 = low), although our data appear to differ somewhat (see
Section 5.1 below).
https://doi.org/10.1017/S0025100316000293 Published online by Cambridge University Press