Closure duration versus f0 perturbation as a cue to underlying stops for the American English intervocalic flap

Researchers found that there are five main cues for distinguishing the voicing of these intervocalic plosives, preceding vowel duration, following vowel duration, closure duration, semantic context, and f0 perturbation, also known as consonant intrinsic f0. In American English, when /t/ and /d/ occur intervocalically, they are realized as a voiced alveolar flap [ɾ] (e.g., [ɹa͡ɪɾɪŋ] writing/riding, [liɾɚ] liter/leader). The presence of these cues indicates incomplete neutralization of these forms. To address a current gap in the literature, the present study focused on American English native speakers’ perception and use of CF0 and closure duration as independent and combined informative cues for deciding voicing contrast of /t/ and /d/ when neutralized by the flap. Participants engaged in a self-administered online forced-judgement task of a pseudoword in 30 combinations of CF0 and flap closure duration to indicate the underlying representation (/hɑtɑ/ or /hɑdɑ/) of the surface production [hɑɾɑ] they perceived. This study observed that participants are more likely to select /hɑtɑ/ when the CF0 is higher and / hɑdɑ/ elsewhere. These modest findings suggest that CF0 is a useful cue for voicing distinction. The results suggest that models of spoken word recognition and speech perception ought to include CF0 as a cue.