It can occur in the height of the vowel space
(optimal), in the nose (nasal tone), or in the throat (breathy or pressed tone).
Dispersion Theory claims that the vowels of a given language are arranged in the acoustic vowel space
in such a manner that the potential for perceptual confusion between the distinct vowel categories is minimized.
Furthermore the vowel inventories of the vast majority of the worlds languages include the three vowels that define the extremes of the general vowel space
namely /i a u/.
Similarly, in Chuxnaban Mixe [ae, o, y] do not penetrate the vowel space
of other phonemic vowels, as shown in Figures 20 and 21.
It is possible to put the two most important of them, F1 and F2, into a combined articulatory/auditory and acoustic vowel space
However such investigations of DT placing emphasis on inter category distance as the determiner of vowel system configuration in a universally defined acoustic vowel space
have failed to account for some systems like Swedish where nine vowels crowed in a small corner of the entire vowel space
rather than dispersing them throughout the available space (Disner 1983).
Lindau's view, in turn, is that "[l]ong and tense vowels are more peripheral in the auditory/acoustic vowel space
, while short and lax vowels are more central" (1978: 557), so that "[t]he difference between tense and lax vowels is best labeled by a feature Peripheral" (1978: 558) which is "best described with reference to the acoustic domain" (1978: 541), that is, as the "amount of centralization on [an] acoustic chart" (1978: 559).
Both front and back vowel spaces
are divided into two regions of phonological space: a peripheral region, near the outside of the vowel space
, and a nonperipheral one, closer to the center" (1994: 32).
VOWEL QUALITY TECHNIQUES AND THE REDUCED VOWEL SPACE
but it may suggest the difficulty of allocating a specific point in the vowel space
for what he considers to be a reduced vowel.
In addition, the vowel space
shows plottings for a more accurate quality in Norwegian compared to German (Figure 1).
in the high-mid area of vowel space
, intrinsic duration plays the role of a secondary feature to enhance perceptual contrast between vowels, whereas in the area of mid-low oppositions the distance is large enough to guarantee the necessary perceptual contrast by spectral features alone and an additional cue like intrinsic duration of a vowel is less essential.