Is there a steady transition between unrounded, 'outrounded', and 'inrounded' Swedish vowels, or are these distinct categories? By which articulatory parameters can these distinctions be described? These questions, actualised through confusion data in speechreading, are answered by means of articulatory measurements of lip-opening, lip-protrusion, and jaw-lowering in 4 subjects. It is found, i.a., that rounded and unrounded vowels form clearly separated categories, and that inrounded vowels, including /o/, are distinguished from outrounded ones by their smaller lip-opening and, if long, by increased lowering of the jaw.
1979. Vol. 36, no 1, 44-56 p.