Speech rate effects on linguistic change

This work is couched in the Articulatory Phonology theoretical framework, and it discusses the possible role of speech rate on diachronic change from antepenultimate stress words to penultimate stress words. In this kind of change, there is deletion of the medial (or final) post-stressed vowel of the antepenultimate stress words. Our results suggest that speech rate can explain this historical process of linguistic change, since the medial post-stressed vowel reduces more, although without deletion, than the final post-stressed vowel from normal to fast rate. These results were confirmed by Friedman's ANOVA. A one-way ANOVA also indicated that the duration of the medial post-stressed vowel is significantly smaller than the duration of the final post-stressed vowel. On the other hand, words such as “fôlego” (breath) and “sábado” (Saturday) reduce less their post-stressed segments in comparison with words such as “abóbora” (pumpkin). This finding, associated to Brazilian Portuguese phonotactic restrictions, can explain why forms such as “folgo” and “sabdo” are not frequently found in this language. Besides, linguistic changes influenced by speech rate act according to dialect and gender. In this paper, speakers from the Mineiro dialect (from Minas Gerais state) (rate: 7.5 syllables/sec.) reduced the medial post-stressed vowel more than speakers from the Paulista dialect (from São Paulo state) (rate: 6.4 syllables/second), and male speakers (rate: 5.8 syllables/sec.) reduced the medial post-stressed vowel more than female speakers (rate: 5.2 syllables/second). These results were also confirmed by one-way ANOVA.