VOWELS IN STANDARD AUSTRIAN GERMAN - Acoustics ...

Sylvia Moosmüller
Son 1993 115 ). Gay (1978) showed that when the vowel is shortened, it is predominantly
the onset that is changed, whereas the vowel midpoint stays invariant. For the vowel /i/,
Gay states:
“For all subjects, the onset frequency of the second formant transition is higher for the fast
rate condition, while the F2 midpoint frequencies and F2 rates of change remain essentially
unaffected across the two rates.” (Gay 1978: 226)
However, the acoustic invariance is not accompanied by articulatory invariance:
“The present acoustic data are also inconsistent with earlier EMG data (Gay et al., 1974, Gay
and Ushijama, 1975) that showed a change in the level of muscle activity for vowels in
response to a change in speaking rate. The EMG data showed that the activity levels of the
genioglossus muscle for the vowel /i/ decreased with an increase of speaking rate”. (Gay
1978: 228).
Compensatory articulatory strategies for guaranteeing a desired acoustic output are very
well documented. Perturbation experiments (Savariaux et al. 1995, 1999, Hoole 1987,
Jones & Munhall 2003) show that subjects try to compensate the perturbation in order
to ensure an improvement of the acoustic output 116 . Men and women use different
strategies in the production of back rounded vowels, which, in both cases, guarantee a
sufficiently low F2 (Fant 2004). Furthermore, speakers adjust their articulation accor-
ding to individual vocal tract shapes. Perkell (1997) could show that tongue height in
the production of the vowels /i, ç, E/ differed according to the individual shapes of the
palate.
“The speaker with the shallowest palate vault (1) uses the smallest adjustments of tongue
height to create the area function differences required for the vowels, and the speaker with
one of the steepest vaults (3) uses the largest adjustments.” (Perkell 1997: 350)
Similar results were obtained by Pouplier et al. (2004) in their study on the tense – lax
distinction in German:
“There is considerable inter- and intrasubject variability as to the palatal distance within a
tense and lax pair.” (Pouplier et al. 2004: 24)
115 van Son (1993) concluded that target-undershoot is most probably planned.
116 Löfqvist (1997) argues that the fact that speakers needed several trials to obtain the
desired acoustic output, speaks against acoustically-based targets, whereas for Perkell
(1997) several trials are no counterargument against acoustically-based targets and are
compatible with this concept, because, in bite-block experiments, subjects acquired an
alternative set of motor command-to-acoustic mappings and retained this set for later
recall (1997: 364)
176