Is clear speech tailored to counter the effect of specific adverse listening conditions?

The study investigated the perception of speech produced to counter the effects of adverse listening conditions. Participants completed a problem-solving task with an interlocutor in good listening conditions (NB) or with the interlocutor hearing them via a vocoder (VOC) or babble (BAB). Keywords extracted from recordings were presented in babble for initial consonant identification. BAB tokens were identified faster than VOC or NB tokens even though VOC and BAB tokens were rated as similarly clear. Acoustic measures showed clarifications to be global rather than specifically enhancing phonological contrasts. These results suggest that clear speaking styles are tailored to listeners' needs.