Frequency distribution and spreading behavior of different types of mouth actions in three sign languages

In this paper, we present a comparative study of mouth actions in three European sign languages: British Sign Language (BSL), Nederlandse Gebarentaal (Sign Language of the Netherlands, NGT), and Swedish Sign Language (SSL). We propose a typology for, and report the frequency distribution of, the different types of mouth actions observed. In accordance with previous studies, we find the three languages remarkably similar — both in the types of mouth actions they use, and in how these mouth actions are distributed. We then describe how mouth actions can extend over more than one manual sign. This spreading of mouth actions is the primary focus of this paper. Based on an analysis of comparable narrative material in the three languages, we demonstrate that the direction as well as the source and goal of spreading may be language-specific.