Cancer in the head and neck area and its treatment can have debilitating effects on communication. Currently available treatment options such as radiotherapy, surgery, chemo-radiation, or a combination of these can often be curative. However, each of these options affects parts of the vocal tract and/or voice to a more or lesser degree. When the vocal tract or voice no longer functions optimally, this affects communication. The aim is to gain insight into the communicative difficulties encountered by this population, and whether speakers adapt to their physical limitations (learn to compensate). It is assumed that the physiological limitations place constraints on certain communicative and language functions, and ultimately affects language behaviour. Acquiring a sign language as a first or second language is acquisition in a visual-spatial modality. This characteristic has an important influence on the acquisition process, for example, although other aspects of acquisition are comparable to acquisition in spoken languages. The goal of the research group is to examine the effects of the visual-spatial modality on acquisition and processing of signed languages and to implement that knowledge in applied areas. There are several projects that fall into this area. The situation of a child learning a sign language, whether hearing or deaf, is almost always bilingual in that the sign language and spoken language are simultaneously combined leading to an unusual type of code-mixing, called code-blending. Variation in the input can have an influence on the acquisition process. Attention for language in the visual modality is an aspect a child has to learn. This leads into turn-taking where sign languages make use of specific visual means; sign languages studied to date seem to indicate considerable amounts of floor-sharing.