Predictability of head movements as feedback signals in signed and spoken languages
Simona Sbranna, Simon Wehrle, Anastasia Bauer, Sonja Gipper, Tobias-Alexander Herrmann, Jana Hosemann
University of Cologne, Germany
Head movements are commonly used as feedback signals in both signed and spoken face-to-face interactions (McClave, 2000; Stivers, 2008; Puupponen et al., 2015, Mesch, 2016). While research on non-vocal feedback in spoken language is extensive, not much is known about the use of head movements in signed conversation as a form of non-manual feedback, although it is considered fundamental for mutual understanding in the signed modality (Mesch, 2016). Moreover, no comparative studies have been conducted on this topic so far across the two language modalities. In this exploratory study, we analyse 30 minutes of dyadic interactions in four languages: German and Russian sign language, and spoken German and Russian (three dyads per language). We quantify how diverse and predictable the production of head movements is across languages using the measure of Shannon entropy (as applied to spoken feedback signals in Wehrle, 2021). This measure gives an insight into the degree of routinization (less variable, more predictable) and creativity (more variable, less predictable) in the use of head movements as feedback signals. Preliminary results based on a reduced dataset suggest that signed languages present more predictable behaviour than spoken languages (entropy (H) 0.69 vs. 1.24), with a strong overall preference for head nods (Fig.1), and a comparatively increased proportion of head tilts in the spoken modality. This result might be interpreted as an attempt not to overload the visual channel in signed languages.
References
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- Wehrle S. (2021). Multi-Dimensional Analysis of Conversation and Intonation in Autism Spectrum Disorder. PhD Thesis, University of Cologne.