Phonetic Fieldwork: Working on
Tone
2010 Summer School on Documentary
Linguistics in West Africa (Intermediate)
July 19-July 31 2010
What is tone and why work on it? (1)
“A language with tone is one in which an indication of pitch
enters into the lexical realization of at least some
morphemes” (Hyman 2001: 1368).
This definition includes the possibilities of pitch variations being:
What is tone and why work on it? (2)
• lexically contrastive
and/or
• grammatically contrastive
and of there being
• tonal morphemes
and/or
• toneless syllables
What is tone and why work on it? (3)
• given the phonemic and grammatical importance of tone, it
cannot be ignored in a fieldwork situation any more than one
might ignore vowels.
• a substantial literature exists; the fieldworker should
familiarize him/herself with it before undertaking fieldwork.
Importance of training in practical phonetics in
doing fieldwork on tone
• one of the most important prerequisites to doing good
fieldwork is to have sufficient training in practical phonetics
• one needs at least to be able to hear and identify new and
unfamiliar sounds, and to have the ability to overcome the
phonological filter imposed by one’s own language
• equally true of both segmental and tonal material
The importance of tone
• most languages are tonal
• tone functions at various levels
– lexical (phonological)
– grammatical (morphological)
– pragmatic
– deictic
Importance of tone: Lexical tone
Word
ɔ́bɔ́ŋ
ɔ́ bɔ́ɔ́ŋ
ɔ́bɔ̀ŋ
Tone
H
H
L
Gloss
mosquito
chief
cane
Table 1: Contrastive lexical tone in Ibibio
Importance of tone: Lexical tone
Word
baŋ
Tone
1
2
3
4
Gloss
defensive trench around village
a type of wild cat (genet?)
begin
a wound
Table 2: Contrastive lexical tone in Mambila
Importance of tone: grammatical tone
Mambila Negation
1. Affirmative
mè yı̄ lá à
‘I call her/him.’
1S call 3S
2. Negative
mè à yıĺ á ŋɡwé
1S 3S call NEG
‘I do not call her/him.’
Importance of tone: use tone in pragmatic
function
Efik
1. Verb focus
ń déb ḿmɔ́ŋ
I’m buying water.
2. Post verb focus
ńdèb ḿmɔ́ŋ
I’m buying water.
Phonetics of tone: Pitch
• tone associated with variations in fundamental frequency (F0)
or pitch
• F0 is the rate of vibration of the vocal folds
– variations can in principle be tonally relevant on any voiced
segment (but not all pitch is ‘tone’)
• pitch is a relative, auditory, characteristic of speech; a given
sound is higher or lower in pitch than another sound, rather
than high or low in absolute terms
Relative nature of pitch
• men and women and children have, in general, lower and
higher pitched voices respectively
• within each group there are individual differences
• a given individual may have a higher or lower pitch range than
another, and a person’s pitch range may vary under different
circumstances
• such differences are generally not important in a fieldwork
situation; they are normalized in the speech perception
process
Variable nature of pitch
• a given speaker may use a different pitch range on different
occasions, or even within the same ‘occasion’, e.g. an elicitation
session
• various paralinguistic or external influences may trigger such
variation
• some aspects of pitch variation are potentially problematic in doing
field work …
• one particular problematic area is that intonation is also produced
mainly with pitch variations, which may perturb tone realizations
Importance of working with several speakers
• the problems associated with the relative and variable nature
of tone demand that one works with several different
speakers;
– comparing across speakers allows us to extract the
common pattern in cases of variability
Pitch and microprosody (1)
• pitch is analyzed as separate from the segmental stream
– it is not a feature of the vowel or consonant which carries it
– but it is not unaffected by segmental features
• consonants on either side of the vowel have a perturbing effect on
F0.
– voiceless obstruents tend to increase F0
– voiced obstruents lower it
• nasals and laterals (and other sonorants), have little effect on F0
Pitch and microprosody (2)
• vowels also have an influence on F0, known as intrinsic vowel
– high vowels have a higher F0 than low vowels, ceterus
paribus
• these factors may have an influence on how tones are
perceived and identified
Phonetics of tone: Duration
• duration may be relevant to tonal distinctions
– contour tones may be longer than level tones
– they are typically comprised of two or more level tones
• duration may therefore serve as a secondary cue for tone
• few studies have reported durational differences associated
with tone in African languages
Phonetics of tone: Amplitude
• amplitude may be relevant to tonal contrasts
• amplitude pertains to the loudness of a given sound relative to
neighbouring sounds
• so (hypothetically) a given tone may be louder (or quieter) than
other tones in the inventory
• there is a known relationship between pitch and loudness
• little research done on this, especially regarding the languages of
Africa
Phonetics of tone: Phonation type
• phonation type (or voice quality) refers to the mode of
vibration of the vocal folds
• well known contributor to tone contrasts in SE Asian
languages, e.g. Vietnamese (creaky voice associated with low
tone)
• rarely shown to contribute to tone in African languages,
though little research has gone so far as to even consider the
possibility
Eliciting tone: Preliminaries (1)
• bound together with eliciting other material, principally
through lexical eliciation
• we elicit wordlists of basic vocabulary; segmental material is
transcribed; indication of pitch variations needs to be
included
• so, to transcribe tone, one must first be aware of the need to
transcribe it (see above)
Eliciting tone: Preliminaries (2)
• field work manuals suggest having the informant or language
assistant whistle the pitch pattern of the word or phrase being
elicited, as an aid to hearing the pitch changes in the absence
of distracting segmental material
– but not everyone can whistle well, and it is harder – for
many people – to accurately reproduce pitch differences
• so, humming is often preferable
– everyone can hum
– it involves using the vocal folds (F0) to create pitch
Eliciting tone: Preliminaries (3)
• even single words pronounced in isolation (as in wordlist
elicitation) constitute an utterance or phrase
• so may carry pitch features associated with utterances as
opposed or in addition to those of words
• therefore it is important to work with longer stretches of
speech in addition to ‘isolated’ forms
– this allows the target word to be placed in different
contexts
Eliciting tone: Preliminaries (4)
• the relative nature of pitch means eliciting isolated words (as
in a wordlist) may lead to difficulties identifying tone
• it difficult to know which tone indicates a given meaning
when words are given in isolation
• e.g. in Mambila, baŋ has four meanings, identified by one of
four level tones
– but heard in isolation it may be difficult to distinguish one
tone from another
Eliciting tone: using a frame
• one means solve this problem to is to use a constant frame,
with elicited words embedded in this frame
• e.g. in Mambila, the plural marker is bɔ̀, i.e. always with a L
tone
• so, combining countable nouns with PL allows one to establish
tone height relative to L:
bɔ̀ bàŋ ‘a wound’
bɔ̀ bāŋ ‘genets’
bɔ̀ báŋ ‘defensive trenches’
Eliciting tone: using a frame
• using a longer frame, where the target word can be inserted
in the middle may be more desirable, but may not be possible
very early in the research
• e.g. in Mambila, the sentence ‘say ___ quickly’ is pronounced
entirely on tone one (High), so target words can be inserted in
the blank:
túé ____ wáɡá chén
Eliciting tone: alternating word sequences
• the problem of phrase level effects can be solved by using
sentences where the target word can be heard at different
places within the phrase; or more simply, by stringing
together different tone combinations in different sequences,
e.g:
bàŋ, bāŋ, baŋ, báŋ;
báŋ, bàŋ, bāŋ, baŋ;
báŋ, baŋ, bāŋ bàŋ;
ETC.
How many tone contrasts in a language? (1)
• the number of contrasts is first and foremost a phonological
problem which may not be completely solved in the field
• as with segmental material there is no guarantee one will find
minimal sets to illustrate the entire tone inventory –
especially if it is a relatively large one as found in Mambila
How many tone contrasts? (2)
• Hyman’s definition of a tone language indicates some
syllables/words may be inherently toneless
• the verbs of many Edoid languages, for example, are
inherently toneless
• in such languages tone may be found to play a larger role at
the morphological or grammatical level than lexically.
How many tone contrasts? (3) Levels vs contours
• a question for phonology, which again may or may not be
solved in the field
• traditionally, African languages have been known as ‘register’
tone languages; i.e. the tonal targets are different pitch
heights and tones are typically level
• contours that exist on the surface are combinations of tones
of different levels
• nonetheless at some stage in the investigation the underlying
nature of the levels must be established
Recording tone
• the basic principles followed in recording tone are the same
as those used in recording other speech samples to be
included in a documentation: aim for the best quality possible
• such recordings are at least dual purpose
1. to provide representative samples for
documenting/archiving
2. to provide data suitable for instrumental analysis –
whether or not the fieldworker him/herself intends to
do such work.
Experimental fieldwork on tone
• experimental phonetics and phonology on tone may be done
after the basics of the tone system has been established
• experimental work typically uses between five and ten
speakers, though ideally more:
• ten speakers, balanced for gender, age and other
possible intervening factors
• when working with endangered languages, it is often
not possible to have a neatly balanced speaker pool
Speech materials for experimental work
• Speech materials used must take both of the purposes
mentioned into account
• an important consideration in developing speech materials for
investigating tone is to control for microprosodic effects
• e.g. the perturbations of F0 created at the consonantvowel interfaces, which are most severe with voiceless
obstruents, and may be avoided, largely if not totally,
by using words containing nasals and laterals when
possible.
Tone research in speech production and
perception
• research production on tone production (and pitch realization
generally) allows us to establish the physical factors that may
govern tone production
• such research should be combined with investigation into
speech perception, to determine the relative perceptual
saliency of these physical factors (see e.g. Connell 2001, Ding
2007, Hombert (1988)
Some research issues with tone and pitch
realization
• establishing the contribution of the different phonetic
features which may contribute to tone
• determining the relative contribution of tone and other pitch
based phenomena to the overall pitch contour of an utterance
• the phonetic (and phonological) effect of automatic vs nonautomatic downstep
• the contribution of tone and other pitch based phenomena in
distinguishing questions and statements
Some experimental paradigms in investigating
tone and pitch
• using prompts: speakers read prepared material
• role play: speakers interrogate/respond to each other
• map task experiments
• perception experiments: hearers identify representatives of
different tones
Documenting/Archiving tone material
• Little has been said in the literature on language
documentation as to what should be included in a
documentation with respect to tone material, or how how
such material should be prepared/presented
– Himmelmann (2006), Himmelmann & Ladd (2008) while
dealing with prosody in documentation and in fieldwork
respectively, essentially skirt the issue of tone
Documenting/Archiving tone material
• open to discussion, but …
• certainly recordings, from more than one speaker
• representative samples of all contrastive tones and
permissible combinations of tones in the language
• annotated audio files (e.g. in praat)
– with waveform and/or spectrogram, pitch trace,
annotation tiers
Bibiography
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Connell, B. & A. Akinlabi (2008). Phonetics and Phonology in Language
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