perilus v - Stockholms universitet

speeding up their articu latory movements (Kuehn and Mo ll, 1976;
Gay, 1981). An increase of coarticu lation with a faster speaking
rate has also been shown for Swedish by Engstrand and
Nordstrand
(1983) through measurements of initia l and media l formant
frequencies in vowe ls (corresponding to locus and target in this
investigation). Moreover, Engstrand (forthcoming) measured
utterances of two Centra l Swedish speakers, especia lly Ipi pu
pal, on x-ray fi lm. He found re lative ly litt le coarticu lation
when speech rate and stress were norma l; at a fast speech rate
coarticu lation increased,
especia lly in stressed sy l lab les.
It is also possib le that a dimension of more or less clear
pronounciation - "hypo" and "hyper" speech - has inf luenced the
coarticu lation in our experiment.
This dimension can be
independent of speech rate, though
instead dependent on,
for
example, socia lly or communicative ly determined factors (Lindb lom
and Lindgren, 1985) .
A
special exp lanation is necessary for the locus-target relation
in bara: why is there not the same amount of coarticu lation here
as in the rest of the words beginning with IbVI or even those
beginning
with
Iba/? In Swedish the phoneme lal has two
phonological ly
distinct lengths. The length distinction is
accompanied by a dif ference in timbre whose main acoustic
correlate is the frequency of the second formant: the long
variant has an F2 of about 1000Hz for ma le speakers whi le the
corresponding frequency in the short variant is about 1250Hz.
Dif ferences in timbre between short and long vowe ls can be
perceptually re levant even if the length distinction is removed
(Hadding-Koch and Abramson, 1964) . Thus when depending on e. g.
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