What motivates high vowel deletion in Québec French: foot structure or tonal profile?

Previous studies have argued that high vowel deletion (HVD) in Québec French is constrained by iterative iambic footing (Guzzo, Goad & Garcia 2016, Garcia, Goad & Guzzo 2017; see also Verluyten 1982), since it preferentially applies in even-numbered syllables from the right edge of the word. In this paper, we compare this hypothesis with an alternative hypothesis: HVD is constrained by the optionally-realized phrase-initial H tone (Jun & Fougeron 2000, Thibault & Ouellet 1996). We report on a judgement task in which two- and four-syllable nouns with HVD in the initial syllable are placed in phrases of different profiles (No determiner, Determiner + noun, Determiner + adjective + noun). If tonal profile plays a role in HVD, HVD in four-syllable nouns in phrases where the noun is in isolation or preceded by a determiner alone should be dispreferred, since the initial syllable of the noun is assigned the optional H tone in these contexts. Our results do not confirm this: HVD is favored in four-syllable nouns over two-syllable nouns, regardless of phrase type. We explain this finding by expanding our previous proposal: HVD is regulated by foot structure, but is dispreferred when it targets the head foot (where the obligatory phrase-final prominence is realized).