From: (1995) Working Papers in Linguistics: Department of University of Hawaii at Manoa, Vol. 27: 1-13.

TONAL FEATURES AND THE DEVELOPMENT
OF VIETNAMESE TONES
MARK ALVES
In describing the development of tones and register in Southeast and East Asia, several
phonetic features need to be considered: various dimensions of pitch (e.g. height and contour), phonation type features (e.g. breathiness and creakiness), and length (i.e intrinsic tonal
duration). Vietnamese as seen as a link between two linguistic areas with different types of
suprasegmental features, namely Chinese tones versus Mon-Khmer register shows complex
bundles of features in its tonal system, features that interacted to generate the conditions for
tonal contour, if not tonogenesis. This study will add to Haudricourt’s proposal (1954) for
Vietnamese tonogenesis by looking at how feature enhancement played a role in Vietnamese
tonogenesis. This study also modifies Haudricourt’s proposed order of tonal development and
shows how—historically, genetically, and phonetically—another order of development
obtains involving three stages of tonal development followed by a tonal split. Another aspect
of this study is to formalize the phonological relationship among tones, phonation features,
tonal length, and the tone-bearing units.

1. INTRODUCTION. This study attempts to support the following points:
(a) Tones, in this case Vietnamese tones, consist of a number of phonologically
significant phonetic features. In addition to tonal contour and height, which are considered
the more salient features of tone (and thus the more noted in the linguistic literature on tone),
varieties of tonal phonation and length are important in understanding both the synchronic
representation and diachronic development of tone.
(b) Vietnamese tones could only have arisen through the interaction of a number of
glottal and pharyngeal phonetic phonation features (as opposed to simply ‘borrowing’ tones
through language contact), which, over time, ‘enhanced’ each other to the point of creating
phonemically lexical pitch which still contained the phonation features.
(c) There has to be a phonetically logical sequence of tonogenesis and tone splits. For
Vietnamese, a Mon-Khmer language that had creaky vowels before it had tones, it makes
sense both phonetically and historically to posit that tonogenesis occurred in more than one

stage, in which both creaky vowels and final stops independently developed one tone
category before syllables with final fricatives developed another category. Some evidence
from Ruc, a Vietic language, will be provided.
All of these claims are discussed with some focus on the relation between tonogenesis
and length as well as the concept of feature enhancement and the features involved in the
tonogenesis process. Thus, this study is a preliminary attempt to formalize the features
associated with Vietnamese tones. Since these features are endemic to the region of East and
Southeast Asia, they could be used to describe the tonal systems of other languages as well.
2. TONAL AND REGISTRAL FEATURES. Tones are typically considered to be
suprasegmental phonemes based on pitch height and contour. This can be seen in works such
as Pike’s (1948) analysis of tone, in which he discussed tone in terms of pitch, height (what
he called ‘register’), and combinations of them. Y.R. Chao’s five-number system to
represent tonal pitch height (5 as the highest and 1 as the lowest) is commonly employed by


linguists in discussing tonal languages and in dealing with phonetic description of tones.
Wang (1967) analyzed Chinese tones in terms of seven features that all pertained to pitch
height and contour. Those features include the presence or absence of contour; the three
heights high, central, mid; and the three contour types rising, falling, and convex. In terms of
tone height and contour, there are other factors that can be included, such as (1) average
pitch, (2) direction, (3) length, (4) extreme endpoint, and (5) slope (Gandour 1983).
Clearly, the term ‘tone’ does have to do with pitch contour and height, but in a discussion
of the phonetic and phonemic features of ‘tones’, then other nonpitch features are involved,
either in allophony or even in lexically distinctive features. Consider some of the relevant
features seen in acoustic phonetic studies of tone.
The physical concomitants of prosody include fundamental frequency,
duration, intensity, harmonics and spectral energy distribution from which
linguistic categories, such as tone, stress, vowel length, phrasing and
(linguistic) intonation, as well as expressive categories, such as (affective)
intonation, timbre, tempo and melody, are constructed (Ross et al. 1986).

Hereafter, the term ‘tone’ refers to a suprasegmental lexically distinctive complex of pitch
height and pitch contour, but also length and a variety of emic and etic manifestations of
phonation. Listening to most any tonal language, one can easily perceive other sorts of
phonetic features (besides height and contour) of a language’s tonemes that help distinguish
the tones. The Mandarin third/dipping tone is the classic example of a tone with phonation, a
glottal creakiness that, at least in isolation (excluding tonal sandhi), distinguishes it from
other tones. Wu dialects have tones which are sometimes described as ‘breathy’ (Ramsey
1987), another kind of glottal phonation. Thai is said to have tones that differ primarily in
phonation rather than contour (Uri Tadmor, personal communication).
These tonal phonation features, such as glottalization and breathiness, are some of the
same features that are common in the vocalic register systems of Mon-Khmer languages.
The division between the first and second register (usually considered to be conditioned by
the voicing of the initial consonant either synchronically or diachronically) is seen in a
variety of segmental phonetic effects, including the same sorts of features which are
included among the suprasegmental tone features in tonal languages. Consider table 1, taken
from Matisoff 1973.
Tense-larynx
higher pitch/rising contour
association with -/
voicelessness
retracted tongue-root
‘creaky’ laryngeal turbulence
larynx tense and/or raised =
reduced supraglottal cavity

Lax-larynx
lower pitch/falling contour
association with -h
voicedness, breathiness
advanced tongue-root

‘rasping’ laryngeal turbulence
larynx lax and/or lowered =
distended supraglottal cavity

TABLE 1: Laryngeal features

The kinds of description for these include seemingly impressionistic terms such as
‘breathiness’, ‘creaky’, and ‘raspy’. Other seemingly more objective descriptions include
pitch and contour, tongue-root position, larynx tenseness, and voicing. Similar features are


seen in table 2, taken from Gregerson 1976. In addition, there are features that include vowel
qualities such as open/closed and ongliding or diphthongs.
Register
first

Initial Consonant
(original) surds

second

(original) sonants

Voice Quality
normal head, clear,
tense
deep, breathy,
sepulchral, relaxed

Vowel Quality

more open,
onglided
close, centering
diphthongs

Pitch
relatively higher
pitch
relatively lower
(larynx also
lowered)

TABLE 2: Registral features

What needs to be acknowledged here is that, despite some of the so-called
‘impressionistic’ descriptions, these phonation features need to be taken quite seriously in
terms of their use in phonological systems and their effects on the development of the
phonology of languages with register. Though they are not as easy to define as point or
manner of articulation, these kinds of glottal and laryngeal sounds need to be regarded as
phonemically significant. So ‘breathy’, for example, is not just a description, but is also a
distinctive feature. An attempt at formalizing these features is seen in the study by Headley
(1976) that showed how pharyngeal features could be used to analyze Sre vowels and other
Mon-Khmer and West African languages with pharyngeal expansion.
Formalized phonation features can thus be used in a phonological analysis of register
languages that show numerous significant phonation features. Moreover, the features in
question can be shown to have interacted diachronically, resulting in various phonological
consequences. The transference of register and tone from one language to another through
language contact can also be better understood when the phonological and phonetic features
are clearly distinguished. Section 5 provides a phonological analysis of these features.
Before that, sections 3 and 4 will further discuss register in Mon-Khmer languages and

Vietnamese tonogenesis.
3. PHONOLOGICAL EFFECTS OF PHONATION AND REGISTER. There are numerous phonetic
and phonological consequences of register that can be seen both synchronically and
diachronically. Though these effects vary according to language, there is a general tendency
of change. Table 3 (Huffman 1985) shows five stages of registral effect in Mon-Khmer
languages, with a sample language for each category. Some languages have not changed or
show intermediate stages of change to a register system. Others have developed full register
systems. Still others have undergone changes of the vowel system due to the complete or
partial loss of register. Finally, at the end of the continuum, tones may develop.
Voicing
1. -v
2. +v
example

Proto-lg
kaa
gaa
--

Conservative
kaa
gaa
Stieng

Transitional
kaa
k’aa
Souei

Register

kaa
kàa
Mongkong

Restructured
kaa
kia
Khmer

Tonal
káa
kàa
Vietnamese

TABLE 3: Stages of registral effects

The particularly direction of the splits (such as first register showing clear voice in one
language and creaky in another) in each case is not as important as the fact that the splits


occur at all.1 The Austronesian Chamic languages, in contact with Mon-Khmer languages in
Vietnam, have shown the same kinds of changes (Thurgood 1996), suggesting that these
sorts of changes are naturally motivated and, thus, can be phonologically explained.
Regardless of the theoretical view, register and related phonation clearly have had a
tremendous impact on both the vocalic and tonal systems of the languages in question.
4. TONOGENESIS AND REGISTER. Haudricourt (1954) was able to break down the barrier
between Vietnamese and Mon-Khmer languages (as opposed to genetic affiliation with Tai,
Maspero 1912) by positing tonogenesis in Vietnamese. He saw numerous correspondences
between the tones of Vietnamese and certain sounds in Mon-Khmer languages. These
correspondences have been fairly well supported by later studies (cf. Gregerson and Thomas

1974, Huffman 1977). Haudricourt’s hypothesis, whereby pitch contour was derived from
the final of the syllable and the pitch height then split into high and low based on the voicing
of the initial, is seen in table 4. (Note: The numbers 1 to 6 as seen in table 4 will be used
hereafter when referring to Vietnamese tones, 1 to 3 being the high series and 4 to 6 the low
series.)
final
initial
voiceless
voiced

zero/nasal

stop

fricative

1
4

2
5

3
6

TABLE 4: Haudricourt’s tonogenesis hypothesis

Haudricourt posited that Vietnamese tonogenesis began with the generation of two nonlevel
tones which resulted in three tone categories. Then there was a tonal height split, creating six
tones. Eventually, the nonphonemic suprasegmental features became phonemic tonal

distinctions as other sound changes occurred, such as loss of finals and changes in voicing of
the initials. However, Haudricourt did not, at that time, have much access to information
about the possible effects of phonation on Vietnamese tones and registrogenesis.
Diffloth (1989) somewhat tentatively but persuasively showed that he had evidence to
place vocalic creaky voice at the level of proto-Mon-Khmer or perhaps Proto-Austroasiatic.
This dating is important, since the presence of phonetically and/or phonemically significant
phonation in Vietnamese at the time of contact with Chinese could have had significant
consequences on Vietnamese tonogenesis. Assuming that Haudricourt was correct (that
Vietnamese is a Mon-Khmer language), and that Diffloth was correct (that Proto-MonKhmer had creaky voice which shows reflexes in Vietnamese tones), then these phonation
features were most likely present in Vietnamese when the great wave of tonogenesis surged
throughout East and Southeast Asia. Phonation seen in Vietnamese tones should be
originally from phonation features present more than two thousand years ago, as they are not
likely to have come from contact with Chinese.
Phonation has had an even more significant effect on Vietnamese than previously
imagined. As noted by Gage (1985) and Diffloth (1989), a supposed problem in
1

Marc Miyake pointed out to me that Khmer itself shows what could be considered reversed features in
comparison with other Mon-Khmer languages. He also suggested prosodic factors in terms of syllabic stress as
being another factor besides initial voicing. David Thomas (1995 SEALANG e-mail discussion on tone and
register) summarized various registral effects, and in some cases, these effects were the opposite of what the are
in Vietnamese. Nonetheless, the point to be made here is that there is a difference, typically two-way splits.


Haudricourt’s hypothesis of Vietnamese tonogenesis was, in fact, explained in the light of
reflexes of Mon-Khmer languages. According to Haudricourt (1954), final stops resulted in
tones 2 and 5, while open and nasal-final syllables showed tones 1 and 4. There are quite a
number of counter-examples where tones 2 and 5 occurred with open or nasal-final syllables.
Diffloth (ibid.) showed that in a number of Austroasiatic languages (including Talan, Chong,
Song, and Muong), such syllables occurred with creaky voice, which is reconstructible to

Proto-Austroasiatic. Examples are shown in table 5.
Gloss
four
dog
one

Vietnamese
bon2
cỗ2
mot5

Talan
pua/n
cỗ/ỗ
mo/y

Song
pho/n
chỗ/ỗ
moy

TABLE 5: Correspondences

This early form of phonation in Austroasiatic provided the phonetic conditions later for tones
2 and 5 to develop, separate from conditioning by the final. In terms of the final, those tones
appear to be in the category for tones 1 and 4 (i.e. occurring in open or nasal-final syllables),
but phonetically and phonemically, they appear as tones 2 and 5 (i.e. syllables with final
stops). This modification of the tone category in terms of syllable form (splitting syllables
with clear versus creaky vowels) is shown in table 6.


-voice
+voice

clear
1 (a)
4 (à)

creaky
2a (á)
5a (Õ)

stop
2b (á)
5b (Õ)

fricative
3 (ä)
6 (ã)

TABLE 6: Diffloth’s modification

The evidence for creaky voice in proto-Austroasiatic makes a significant contribution to the
understanding of phonation features in Vietnamese: it appears that (1) creaky voice led to
the creation of a tonal category, while (2) the register distinction, related to the F0 and
breathiness, led to the tonal height distinction.2
Thus, the earlier Moh-Khmer creaky vowel quality took part in Vietnamese tonogenesis.
Vietnamese is not the only language to show this. Sagart (1988) showed that in Chinese,
glottalization and breathiness had a role in the development of tones, in particular, the
Chinese departing tone category. That phonation took part in Vietnamese tonogenesis is seen
in the tones themselves. The phonation features that helped create Vietnamese tones in the

first place have not been lost, though they have shifted from the vocalic tier to the tonal tier
to create tones with a complex of features, as will be discussed next. The register distinction
that led to pitch distinctions as features of certain vowels (segmental) in many Mon-Khmer
languages led to tonal (suprasegmental) height distinctions in Vietnamese and other VietMuong languages.

2

Discussions with Marc Miyake helped clarify this distinction between early Austroasiatic vocalic creakiness
and the later development of register that may be a southeast Asian areal feature rather than features from the
Austroasiatic proto-language.


5. VIETNAMESE TONES AND AUSTROASIATIC FEATURE COMPLEXES. In considering
Vietnamese tones, there seems to be what can be called a ‘feature complex’ (LaVaughn
Hayes September 1995, SEALANG e-mail discussion on tone and register). Vietnamese
tones have registral phonation features like those in Mon-Khmer and the pitch contour
features like those of Chinese and Tai. In addition to these features, I posit that length, like
that seen in vowels, needs to be considered an inherent feature of Vietnamese tones.
Consider table 7 (from Thompson 1965). The final column ‘short’ is my own addition to
indicate tonal length. Though it is largely my own impressionistic perception of the
difference of tonal length, there is evidence from an acoustic study of Northern Vietnamese
tones (Han 1966) that a real difference in length is present in tone 5. A plus sign indicates an
intrinsically short tone (tones 2 and 5), a minus indicates a long tone (tones 3 and 6), and
both signs mean that the tone has no inherent length (tones 1 and 4). Though it could be a
low-level phonetic factor conditioning the length (e.g. shortness due to the presence of final
stops), there are historical reasons for the difference. In the next section, I will discuss how
the concept of intrinsic tonal length enters into the development of Vietnamese tones as well
as the modern phonology of Vietnamese.
Tone
2 sac

6 nga
1 ngang
4 huyen
3 hoi
5 nang

high
+
+
+
-

tense
+
+
+
+

glottalic
+
+

short
+
+/+/+

TABLE 7: Vietnamese tone features

In table 7, height is the primary distinction (though tones 3 and 6 have switched height in
modern Vietnamese). Tenseness is not clearly defined by Thompson, but it may have had to

do with the tenseness of the glottis. The feature glottalic indicates the presence of a glottal
break in the tone itself, a significant phonetic feature. Thompson omits the actual tone
contour from this particular description, yet the tones are still distinguished by other features.
I posit that tone contour in Vietnamese may be somewhat overrated. A phonetic study (Earle
1975) showed that the so-called ‘level’ tone (‘level’ according to 13 analysts) is never
pronounced level. The so-called ‘low-falling’ tone was closest among all of the tones to
being ‘level’, but only from onset to midset. In any case, there is a sufficient number of other
tone features, besides contour, to distinguish them. It would be an interesting experiment to
see, when tone contour is removed from pronunciation, whether the tones could still be
differentiated by native speakers.
There are some differences between varieties of Vietnamese. The dialects of Vietnamese
have already been divided into south and north for centuries. Two tones merged in southern
Vietnamese, while northern Vietnamese has preserved six distinct categories. There does
appear to be a difference in length. Table 8 gives an impressionistic view of the length of
tones (and phonation features) on different syllables.
TONE
open1
open4

NORTH
---, breathy

SOUTH
---, breathy


open2
open5
open3
open6

checked2
checked5

long
short, glottal
long (or short, glottal)
long, glottal
short
short, glottal

short
short, breathy/glottal
long
long
short
short, breathy/glottal

TABLE 8: Northern versus Southern Vietnamese tones

Northern and southern varieties of Vietnamese do differ, mainly in the type of phonation.
Northern Vietnamese tones tend to have glottal breaks. A particularly notable tone in
northern Vietnamese is tone 6 with a glottal break in the middle of the contour. In south
Vietnam, the most typical tonal phonation feature is breathiness. In northern Vietnamese,
tone 2 is partially unspecified, since it is longer on open syllables, even to the point of
making it similar to tones 3/6 in southern Vietnamese.
6. LENGTH IN VIETNAMESE TONES. Moira Yip (1989:151) made the claim that ‘...
contour tones must involve association to one TBU, rather than to two vowels or moras’.
What she saw in Chinese was that a tone occurred with one syllable, and that the whole
syllable, not just a vowel or a mora, is the tonal-bearing unit upon which the tone is
dependent. This makes phonetic sense; tones are phonetically dependent on other sonorant

segments for their realization. Phonemically, the TBUs need not be separated into sections
(i.e. vowels or moras) for realizing contour tones. However, this model does not allow for
any interaction between tone and the TBU, placing tones at the complete mercy of the TBU
in terms of length and toneme phonation features. This view of the tone’s dependency on the
TBU does not explain how Vietnamese tones influence their TBU or even suggest that as a
possibility. This influence of tones on the TBU has to do with length.
Han (1966) showed that tone 5 was pronounced 50% shorter than any other Vietnamese
tone. Though in northern speech, tone 2 is longer with open syllables that it is with checked
syllables, in the south, it is pronounced short in either closed or open syllables. Minimal sets
can show how the length of the syllable and the tone it carries interact. The vowel /Q/ in
Vietnamese is considered to be /-short/ and has two moras, but can be shortened by tones 2
and 5, reduced to one mora. Figure 1 illustrates the distinction between vocalic moras and
tonal ‘moras’ on an open syllable with a nonshort vowel.
(example:
length:
tonal moras:
segment:

1
neutral
xx
\/
la1/4

2
short
x
|
la2/5


3
)
long
xx
\/
la3/6

FIGURE 1: Samples of Vietnamese Tonal Length

What has happened is that the length of tones 1 and 4 is controlled by the TBU; thus, on
long syllables, the tones are long, while on short vowels, they are short. Tones 2 and 5
shorten the length of the TBU, and 3 and 6 lengthen the TBU, regardless of the lexical vowel
length. In general, most of the interaction between tone and TBU results in shortening since
9 of the 11 vowels of Vietnamese are nonshort (i.e. containing two moras), though the aspect
of phonation is of course another salient effect of the tone on the TBU.


The tonal length just discussed is not an accident, but must have been conditioned by the
environment in which tonogenesis took place.
tone
length:
mora:
forms:

1)

2)

3)


?
/\
àà
àà
||
\/
par ba1

xx
| |
àà
àà
| |
|/
reh re3

x
|
à
à
|\
|
cỗ/ cỗ2

4)

south
x
|
àà

à
| |
|\
po-n → bon5 or

north
xx
| |
µµ
| |
bon5

FIGURE 2: Historical derivation of Vietnamese tones

Figure 2, which contains boxes 1 through 4, shows hypothetical earlier Mon-Khmer forms
based on modern conservative Mon-Khmer languages, the realization of those forms in
modern Vietnamese, and the relation between the moras of the syllables to the ‘moras’ (to
parallel with the concept of vowel length) of the tone.
Tones 1 and 4, the more level tones, are simply the remnants of a register distinction
having to do with the initial, and are thus neutral in respect to their TBU. That scenario is
shown in box 1. Tones 3 and 6 are long because of a preservation of the original length of
final fricative syllables. Box 2 shows the original form, the loss of the final fricative, and the
long tone resulting from compensatory lengthening. There may have been tones with the
final fricatives, but once those finals were lost, the length of those tones became phonemic.
Tones 2 and 5, the short tones, had developed as a result of final stops. Thus, due to those
tones’ phonetic environment, they could only be short, as vowels followed by final voiceless
stops tend to be phonetically short and because the final does not carry moraic weight. Their
shortness is maintained even in open syllables, seen in box 3. In box 4, we can see the effect
of the creaky voice as posited by Diffloth (1989). Southern Vietnamese shows a short tone,
and in northern Vietnamese, tone is nonshort. Again, due to the loss of certain finals or the

creaky voice, the length of those tones became distinctive.
7. FEATURE ENHANCEMENT. None of the features mentioned above could have singly
developed tones in Vietnamese, but rather they must have developed through natural
processes of phonetic ‘enhancement’. The concept of enhancement (San 1991) is that
features that tend to enhance each other, thereby creating other types of phonetic realizations
with phonological consequences, tend to co-occur. Combinations of features (including
phonation, glottal, and pharyngeal features) have resulted in new features in other
Austroasiatic languages. In Chong (Huffman 1985, Diffloth 1989) a combination of
glottalized/nonglottalized and creaky/breathy vowels gave a four-way distinction. These
features’ interaction has led to phonation shifts, pitch contours, and vowel breaking (Diffloth
1989:145), quite similar to the phonetic features of Vietnamese tones.
Language contact has been considered the single source of tone in Vietnamese, such as
contact with Thai and/or Chinese. Clearly, language contact with Chinese had something to
do with the development of Vietnamese tones, as the tonal system of Vietnamese
corresponds quite directly to the eight-way system of Middle Chinese, but Chinese was not
likely the sole trigger for tonogenesis. Registral influence on Vietnamese tones is implied by
the presence of the phonation features of Vietnamese tones that could not have come from
Chinese. Vietnamese had register at the time of contact with the Chinese, and potentially had
the similar kinds of contours or vowel breaking seen in Chong. It may be just as


presumptuous to presume that Vietnamese did not have tones before contact with the Chinese
as it is to say there were already pre-existing incipient tones due to the interaction of
phonation features at the time of contact.
Phonetically, the F0 distinction between vowels after voiced and unvoiced initials is
minimal. Voiced consonants were shown to be lower than voiceless ones, a difference which
could have caused the difference in the following tone or vowel quality (Hombert 1978),
though not with great phonetic consequences. A spectrographic study on register (Gregerson
1976) showed how vowels’ frequencies due to the voicing of initials differed from fifty to a
few hundred hertz. Still, other phonetic (excluding questions of language contact) factors

had to have applied. Only if the various features in question were to enhance each other
could register/tone complexes come to have phonemic standing, though ultimately, some of
the features were highlighted (e.g. pitch contour) at the expense of others (e.g. phonation).
Stage 1
*reh→
+v initial
VC final

*re-h

Stage 2 (Registrogenesis)
→
re4
V height:low
VC final
Vowel phonation

Stage 3 (Tonogenesis)
tone height:low
V final/tone length:long
tonal phonation

FIGURE 3: Three stages of development

As the case in Chong suggests, pitch or tone contour may have only been a consequence
of the other phonetic factors. Clearly, register and phonation features must have come first,
resulting in pitch contour. Figure 3 shows a hypothesis for the three stages in Vietnamese
from the lack of distinctive phonation, to register, to tonogenesis with the features shifting
from the segmental to the suprasegmental level.
This order of tonal development is better seen in tone reflexes in Ruc, a Viet-Muong

language with presyllables (a typical feature of many Mon-Khmer languages but not of VietMuong languages) and tone on the main syllable. The tonal correspondences between
Vietnamese and Ruc are as shown in table 9 (Nguyen 1988).
Ruc
Viet

-a1
-a1

-a2
-a4

-ap3
-ap2

-ap4
-ap5

(ah?
(a3

ah?)
a6)

TABLE 9: Vietnamese and Ruc tones

It is not clear whether Ruc tone is a development shared with Vietnamese, thus coming from
a protolanguage, or an independent innovation. The languages spoken around Ruc, such as
Bru and other closely related Muong languages, do not have tone, supporting but not proving
the former hypothesis. In any case, the phonetic environment for the tones is the same in
both languages, namely final stops for Ruc tones 3 and 4 corresponding to Vietnamese 2 and

5, while open or nasal final syllables show Ruc tones 1 and 2 for Vietnamese 1 and 4. As
Ruc has not lost the final fricative /h/, it has not developed the final tone category seen in
Vietnamese, which lost the final fricatives and gained a separate tone category. Those tones
do not appear to have any governing conditions.
Does monosyllabism matter? It would seem that two possibilities exist. Vietnamese tone
developed either before or after the reduction from sesquisyllabic forms seen in other MonKhmer languages. However, there is a third possibility. Ruc and Bulang (Paulsen 1992) do
have tones in disyllabic words. The tones occur only on the primary syllable, not the


unstressed presyllable. Vietnamese tones could have developed before Vietnamese became
monosyllabic, and perhaps not all the categories arose at once. In addition to chronological
ordering of tonogenesis, the Ruc and Bulang evidence suggests that the collapse to
monosyllabic forms is not the sole impetus for tonogenesis as some have claimed (Benedict
1996, Matisoff 1973), though it could have heightened chances for the features’ interaction in
the process of tonogenesis. Register and the resulting phonetic features along with
monosyllabification and language contact have led to the modern state of Vietnamese tones.
In any event, there needs to be a way to show how these numerous features may have
interacted. Section 8 provides a list of relevant features and discussion of their mutual
effects.
8. TONAL AND PHONATION FEATURES. In order for linguists to account for phonological
and phonetic phenomena in languages, distinctive features must be utilized with as much
restraint as possible to account for as wide a range as possible. At this point, the relevant
phonological features and their interaction are listed and discussed, with the hope that both
synchronic and diachronic analyses and studies of tonal languages can benefit. As this is a
preliminary study, the goal is to be clear and complete, but also to be flexible enough to be
useful to various theoretical frameworks.
Table 10 is lists the features relevant to tone and register. The table consists of the
feature categories and the specific features needed to describe tones and register. A binary
distinction could also be used, in contrast to the multiple distinctions in the feature column.
A binary split would allow the general grouping of sets of tones, such as the distinction

between level and nonlevel tones, which makes sense diachronically in viewing nonlevel
tones as a single group of phonological innovations, but this also represents a traditional view
by Chinese and Vietnamese for purposes of poetry in which those two categories are
distinguished. This two-way distinction in tone categories is also seen in Vietnamese
morphological reduplication in which the tones of the two syllable forms alternate between
level (tones 1 and 4) and nonlevel (tones 2, 3, 5, and 6), regardless of the specific tone
(Hoang 1979). However, since not all of the logical possibilities of the combinations of the
features has been worked out, a multiple rather than binary feature description is used. The
following is a general discussion about the interaction between the various categories of
features.
An important distinction to keep in mind in analyzing tones both synchronically and
diachronically is the difference between tonal height and tonal contour in tonogenesis.
Tonogenesis shows both ‘contour-genesis’ and ‘pitch-height genesis’, in which the kinds of
related phonation features differ. In general, breathiness tends to be associated with low
tones (e.g. Vietnamese tones 4, 5, and 6) and dipping tones (e.g. Northern Vietnamese tone 3,
Mandarin tone 3). Southern Vietnamese no longer has much of its tonal creakiness, but
rather has breathiness as seen in tones 4 and 5. Height tends to be the result of the phonetic
shape of a syllable, though pre-existing creaky voice may also be a factor.
Tone length is conditioned by the phonetic shape of a syllable. Extremes in the length
range (long or short) leads to other phonation features. An example of a long tone is the
Mandarin third tone, which is a dipping tone with creakiness. Northern Vietnamese tones 3
and 6 both are long and have associated phonation features. The extreme effect tones 5 and 6
have on the TBU in terms of length and glottalic quality is an example of how these related
features interact and can enhance each other for maximal perceptual distinction.


CATEGORY
height

contour


slope

length

phonation

tongue root

FEATURE
5/high
4/less-high
3/mid
2/less- mid
1/low
level
rising
falling
trailing
dipping
even
slight
sharp
curving
neutral
long
short
clear
creaky
breathy

tense
neutral
advanced
retracted

INTERACTION
Lower tones tend to occur with phonation features,
such as breathiness.

Contour may be the result of finals in syllables as
well as vocalic phonation. Dipping tones tend to
show phonation features.

Slope may interact with length and tone height and
may be seen as the result of length.

Length is conditioned by and interacts with (after
phonemicization) the phonetic environment of the
syllable. Shortness tends to occur with phonation.
Phonation may both be the result of and result in
other factors, such as length, contour, and syllable’s
phonetic form.
Tongue root position interacts with the phonetic
shape of the syllable. It tends to interact with
phonation.

TABLE 10: Tonal and phonation features

It is hoped that these features can be used in areas other than simply historical studies.
Using the features listed in table 10, one could study tones in continuous speech, including

things such as how intonation, volume, and speed effect tone. For example, Vietnamese tone
2 tends to be a high level rather than rising tone in rapid speech, a natural phonetic effect
(Thompson 1965). In discourse, the creakiness of tone 6 may be more pronounced for clarity
or reduced in casual speech. For purposes of typological studies, languages with pitch height
distinctions can be grouped with tonal languages, especially when similar phonation features
accompany the height distinctions. Those differences may be seen simply as a range on a
continuum. When other such studies have been done, other universal features or
phonetic/phonological tendencies may arise.
9. CONCLUSION. Though the attempt to formalize the features in question is sketchy, I
hope that the need for the formalization has been justified, and that debate can continue
around the ways in which registral and tonal features work and show natural phonetic and
phonological processes. The issue of tonogenesis is quite interesting, as it involves the
interaction of phonetic features, successive changes and steps that led to tones, and language
contact. It should not be taken for granted that Vietnamese gained tones simply from contact
with Chinese; it seems that contact may have been only a step towards the modern state of
Vietnamese tones with the phonetic and phonological conditions within Vietnamese waiting
to be further motivated to change. Some of the problems with Haudricourt’s hypothesis for
Vietnamese tonogenesis (e.g. improper reflexes in related languages) may have something to
do with several different stages of change rather than the two he originally proposed. I hope
that this study may influence research on tonogenesis and the effects of register and


encourage researchers to use the formal tools available in the field of linguistics to
accomplish this task.
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