PTLC2005 Mitsuhiro Nakamura Parametric Phonetics: 1
Parametric Phonetics: an exercise in the dynamic
characterisation of sound patterns
Mitsuhiro Nakamura, Nihon University
1 Introduction The aim of this paper is to describe the main features of a parametric
approach, or parametric phonetics. The essence of parametric phonetics is evident in its
name: it focuses on the continuous activities of the organs of speech and describes an
utterance in terms of the articulatory parameters involved (e.g. Tench: 1978). A
parameter is ‘a variable, an ingredient which is continually present but changing in value’
(Abercrombie 1965: 123). This analytical approach contrasts with the more familiar
technique, namely a postural (or segmental) approach: it describes speech as a series of
postures at a given instance, although the inherent dynamic nature of speech is implicitly
recognised. This paper is motivated by the belief that more direct links between the two
approaches are necessary in teaching and learning phonetics. We shall begin our
discussion by identifying the place of phonetic transcription in the parametric analysis,
with the intention to dispel the common impression that letters exist ‘in time’ and speech
stands ‘in space.’ We then move on to the type and use of the parametric diagram.
Finally, we consider parametric phonetics as a craft skill in doing research.
2 Parameters and Phonetic Transcription A multichannel representation such as in
Figure 1 serves a number of functions by shifting the focus from characterising speech
as a series of static postures to characterising it as a dynamic articulatory process.
Figure 1. Movements of the velum, tongue, and lips recorded by lateral cinefluorography
during the sentence “Next Monday morning bring three tents for the camping trip.” The
segments blacked in at the top are nasal consonants. A partial phonetic transcription at
the bottom of the illustration identified major articulatory events. The dashed vertical line
marks one example of nearly simultaneous movements of two articulators, in this case,
velum and lips. (adapted from Kent 1983: 69)
2.1 Articulatory timing and coarticulation: It is evident in Figure 1 that the movements of
an articulatory organ overlap in time with those of different articulatory organs or different
parts of the same organ. This is called coarticulation, the realisation of which is
determined language-specifically. For instance, the word ‘morning’ requires the front-toback movement for the three nasal consonants on the one hand and the back-to-front
PTLC2005 Mitsuhiro Nakamura Parametric Phonetics: 2
movement for the two vowels on the other (i.e. [m]→[n]→[ η ] and [ɔ ː ]→[ɪ]). This
‘bidirectional’ interaction is realised as if the lip and velum activities are superimposed on
the diphthongal movement of the tongue (Öhman: 1966). Note in passing that the velum
trajectory for [n] shows a contextual variation: the velum opening is less in degree than
that for the other two nasals. Another example is at the point in ‘camping’ (as shown by
the dashed vertical line): the tongue keeps the positions for [æ] and the lips are closing
for [m], while the velum is raised for [p]. That is, the opening-closing of the velum occurs
during and before the closing gesture of the lips.
2.2 Valving and shaping: The modulation of the individual articulators in Figure 1
represents valving and shaping activities of the vocal tract. The former refers to the
formation and release of constrictions, while the latter refers to the modulation of the
vocal tract shape (e.g. Öhman: 1966). During the articulation of ‘three’ the lips are
involved in secondary articulation. The lips for [ɹ] are approximated to the same degree
as in [f], reflecting the lip protrusion, the preparation for which already occurred during [Ɵ].
Consequently, the overall vocal tract is lengthened. Recent studies such as Browman &
Goldstein (1990) demonstrate that the characteristic configuration of the vocal tract is
achieved by both its general activation and a local activation of the relevant articulator.
Thus, phonetic transcription refers to selected properties of the configurations of the
vocal tract. In other words, the valving and shaping activities of articulatory organs are
annotated with reference to linguistically significant information in the stream of speech.
3 Parametric Diagrams Compared with the continuous trajectories of multiple
articulators which we have observed in Figure 1, the parametric diagram is a short-hand
notation. The crucial difference between the postural and parametric approach lies in the
conceptualisation of the time dimension. As seen in Figure 2, ‘the division into segments
represents a division at right-angles to the time axis, while the division into parameters is
a division parallel to the time axis’ (Abercrombie 1965: 123-124.).
Figure 2. A parametric diagram of the word ‘stand’ (adapted from Catford 1977: 227)
The type and number of the parameters in the diagram depends on the specific purpose
of the study activity. The parameters in Figure 2 might be useful for leading students to
an awareness of the basic functional components of the production of any speech sound.
In contrast, if the degrees of stricture relating to the three cavities are chosen, the
diagram may become similar to Figure 3. Both modes may allow students to incorporate
PTLC2005 Mitsuhiro Nakamura Parametric Phonetics: 3
their own thoughts and understanding, as well as their phonetic knowledge, into the
drawing of the diagram. An analysis is applicable not only for a single word as in Figure
2 but also for a process in connected speech as in Figure 3.
Figure 3. A parametric diagram of the phrase ‘good morning’ showing the movements of
the lips (1), the apex (2), the front (3), and the back (4) (adapted from Tench 1978: 41)
It is often desirable to ease the analysis process by concentrating on the most relevant
parameter(s) in a given situation. Here is one example from my seminar (for 3rd grade
undergraduates who have already taken the English Phonetics course). One group of
students reported the parametric analysis of a gradual change from ‘give me’ to ‘gimme.’
Figure 4 shows the diagram of the two parameters, the velum and the lips, and boxes
represent intervals during which articulators are active in the vocal tract.
Stage 1
[…
v
… ??? …
Dental
Narrow
Bilabial
Close
Stage 3
[
Opening
Closing
Opening
Closing
Velum
Lips
Stage 2
m …]
Dental
Narrow
Bilabial
Close
…m…
Opening
Closing
Bilabial
Close
Figure 4. Parametric diagrams of the phrase [gɪv miː]
It is assumed that the change in question takes three stages from the non-assimilated
form (stage 1) to the completely assimilated form (stage 3). What if the velum misses the
right timing, activated earlier, while the lower lip touches the upper teeth? The voiced
turbulent airflow in [v] becomes weaker as the air escapes from the nasal passage. This
situation (stage 2), as the students proposed, can be described by the voiced labiodental
nasal [ɱ]. This symbol is usually not included in the segment inventory of English the
students are familiar with, but it was present in the IPA chart they looked at analytically.
Thus, by diagramming the selected parameters the ‘new segment’ is discovered.
4 Parametric Phonetics as a Craft Skill in Doing Research A parametric description
links segmental and dynamic characterisations of articulation, which is desirable from
both a practical and a theoretical viewpoint. The framework could be pursued from within
testing-out researches as a phonetics of articulatory coordination. Various assumptions
can be derived from the diagram drawn conventionally or impressionistically. For
PTLC2005 Mitsuhiro Nakamura Parametric Phonetics: 4
instance, in Figure 3, the final [d] in ‘good’ is overlapped by the following [m] in ‘morning’,
which leads to a place assimilation producing [b]: the final [d] is deleted in the traditional
sense and its tip/blade activity is not marked in the diagram. However, another possibility
arises: the closure of the lips masks the release of the tongue tip/blade: the lingual
constriction still remains during the lip closure. This possibility is clearly evidenced by
Browman & Goldstein (1990). Figure 5 demonstrates the fact that the constriction by the
tongue tip/blade is present in the vocal tract but no evidence is traced acoustically. Thus,
diagramming helps develop the assumptions of how the world should be. From the same
perspective, Nakamura (2003) discusses the case of devoiced vowels in Japanese.
Figure 5. X-ray pellet trajectories for ‘perfect memory’ spoken in a word list (left) and in a
phrase (right): the symbols indicate the closing gestures: ‘κ’ = velar plosive; ‘τ’ = alveolar
plosive; and ‘β’ = bilabial nasal. (adapted from Browman & Goldstein 1990: 364)
5 Summary Parametric phonetics offers an idea of how the articulatory activities are
regulated. The exciting thing about this approach is that it goes beyond what it
describes: diagramming by the parameters serves as a mind-map of developing
prescriptive assumptions on various phonetic phenomena. It is important to find the
relationships between the two views of speech, postural and parametric, and to put that
knowledge to greater use in teaching and learning phonetics.
6 References
Abercrombie, David (1965) Parameters and phonemes. In his Studies in Phonetics and
Linguistics. Oxford: Oxford University Press, pp. 120-124.
Browman, Catherine & Louis Goldstein (1990) Tiers in articulatory phonology, with some
implications for casual speech. In J. Kingston & M.E. Beckman (ed.) Papers in
Laboratory Phonology I. Cambridge: Cambridge University Press, pp. 341-376.
Catford, John. C. (1977) Fundamental Problems in Phonetics. Edinburgh: Edinburgh
University Press.
Kent, Raymond D. (1983) The Segmental Organisation of Speech. In P.F. MacNeilage
(ed.) The Production of Speech. New York: Springer-Verlag, pp. 57-89.
Nakamura, Mitsuhiro. (2003) The Spatiotemporal Effects of Vowel Devoicing on Gestural
Coordination: an EPG study. Proceedings of the 15th ICPhS, Barcelona, pp. 3025-3028.
Öhman, S.E.G. (1966) Coarticulation in VCV utterances: spectrographic measurements.
Journal of the Acoustical Society of America, 39, pp. 151-168.
Tench, Paul (1978) On introducing parametric phonetics. Journal of the International
Phonetic Association, vol. 8, pp. 34-46.