Vowel harmony and speech segmentation in Finnish

Finnish vowel harmony rules require that if the vowel in the first syllable of a word belongs to one of two vowel sets, then all subsequent vowels in that word must belong either to the same set or to a neutral set. A harmony mismatch between two syllables containing vowels from the opposing sets thus signals a likely word boundary. We report five experiments showing that Finnish listeners can exploit this information in an on-line speech segmentation task. Listeners found it easier to detect words like hymy at the end of the nonsense string puhymy (where there is a harmony mismatch between the first two syllables) than in the string phyhymy (where there is no mismatch). There was no such effect, however, when the target words appeared at the beginning of the nonsense string (e.g., hymypu vs hymypy). Stronger harmony effects were found for targets containing front harmony vowels (e.g., hymy) than for targets containing back harmony vowels (e.g., pale in kypalo and kupalo). The same pattern of results appeared whether target position within the string was predictable or unpredictable. Harmony mismatch thus appears to provide a useful segmentation cue for the detection of word onsets in Finnish speech. (C) 1997 Academic Press.