Inter-Speech Clicks in an Interspeech Keynote

Clicks are usually described as phoneme realisations in some African languages or as paralinguistic vocalisations, e.g. to signal disapproval or as sound imitation. A more recent discovery is that clicks are, presumably unintentionally, used as discourse markers indexing a new sequence in a conversation or before a word search. In this single-case study, we investigated more than 300 apical clicks of an experienced speaker during a keynote address at an Interspeech conference. The produced clicks occurred only in inter-speech intervals and were often combined with either hesitation particles like "uhm" or audible inhalation. Our observations suggest a link between click production and ingressive airflow as well as indicate that clicks are used as hesitation markers. The rather high frequency of clicks in the analysed sections from the 1hour-talk shows that in larger discourse, the time between articulatory phases consists of more than silence, audible inhalation and typical hesitation particles. The rather large variation in the intensity and duration and particularly the number of bursts of the observed clicks indicates that this prosodic discourse marker seems to be a rather acoustically inconsistent phonetic category.