The prominence of spoken language elements in a sign language

Code-blends in sign languages consist of simultaneously articulated manual signs and spoken language words. These "mouthings" (typically silent articulations) have been observed for many different sign languages. The present study aims to investigate the extent of such bimodal code-mixing in sign languages by investigating the frequency of mouthings produced by deaf users of Sign Language of the Netherlands (NGT), their co-occurrence with pointing signs, and whether any differences can be explained by sociolinguistic variables such as regional origin and age of the signer. We investigated over 10,000 mouth actions from 70 signers, and found that the mouth and the hands are equally active during signing. Moreover, around 80% of all mouth actions are mouthings, while the remaining 20% are unrelated to Dutch. We found frequency differences between individual signers and a small effect for level of education, but not for other sociolinguistic variables. Our results provide genuine evidence that mouthings form an inextricable component of signed interaction. Rather than displaying effects of competition between languages or spoken language suppression, NGT signers demonstrate the potential of the visual modality to conjoin parallel information streams.