A selection from Stockholm University publication database
The effect of emphatic stress on consonant vowel coarticulation
2007. Björn Lindblom (et al.). Journal of the Acoustical Society of America 121 (6), 3802-3813Article
This study assessed the acoustic coarticulatory effects of phrasal accent on [V1.CV2] sequences, when separately applied to V1 or V2, surrounding the voiced stops [b], [d], and [g]. Three adult speakers each produced 360 tokens (six V1 contexts x ten V2 contexts x three stops x two emphasis conditions). Realizing that anticipatory coarticulation of V2 onto the intervocalic C can be influenced by prosodic effects, as well as by vowel context effects, a modified locus equation regression metric was used to isolate the effect of phrasal accent on consonantal F2 onsets,independently of prosodically induced vowel expansion effects. The analyses revealed two main emphasis-dependent effects: systematic differences in F2 onset values and the expected expansion of vowel space. By accounting for the confounding variable of stress-induced vowel space expansion, a small but consistent coarticulatory effect of emphatic stress on the consonant was uncovered in lingually produced stops, but absent in labial stops. Formant calculations based on tube models indicated similarly increased F2 onsets when stressed /d/ and /g/ were simulated with deeper occlusions resulting from more forceful closure movements during phrasal accented speech.
Longitudinal Studies of Variation Sets in Child-directed Speech
2016. Mats Wirén (et al.). The 54th Annual Meeting of the Association for Computational Linguistics, 44-52Conference
One of the characteristics of child-directed speech is its high degree of repetitiousness. Sequences of repetitious utterances with a constant intention, variation sets, have been shown to be correlated with children’s language acquisition. To obtain a baseline for the occurrences of variation sets in Swedish, we annotate 18 parent–child dyads using a generalised definition according to which the varying form may pertain not just to the wording but also to prosody and/or non-verbal cues. To facilitate further empirical investigation, we introduce a surface algorithm for automatic extraction of variation sets which is easily replicable and language-independent. We evaluate the algorithm on the Swedish gold standard, and use it for extracting variation sets in Croatian, English and Russian. We show that the proportion of variation sets in child-directed speech decreases consistently as a function of children's age across Swedish, Croatian, English and Russian.