Movements of the mouth which are based on the articulation of German words have to be distinguished from the other non-manuals. Mouthings are articulated simultaneously with manual and non-manual parts of signs and are mostly voiceless. Nouns seem to occur more often with a mouthing than the other sign classes.
Mouthings in DGS are often associated with the former dominant oral educational system in Germany [Socio-Historical Background 2.4.]. They reveal quantitative variations because signers use them to differing extents. Here different sociolinguistic variables play a role (e.g. language background). Moreover, one part of mouthings seems to be ascribable to ordinary cross-channel situations of language contact. Such mouthings appear as loan elements which occur frequently and have a function in DGS. There are many signs for which native signers state that the mouthing is obligatory.
Mouthings may be reduced to the basic form or the stem of the German word. Such reductions may be due to an adjustment to the structure of the respective sign. The identification of German words used as mouthings is usually not possible by means of the visible movements of the mouth alone. For identification, a contextualization is needed which is provided by the manual and non-manual parts of signs. Reversely, mouthings may act as a hedging or specification for the interpretation of signs. They function in different ways: (i) Mouthings seems to be often redundant. Such mouthings do not add lexical, morphological or syntactic information. In such cases, they convey the same information as the manual articulators. (ii) Mouthings disambiguate between diverse meanings of manually identical signs. The signs butter, jam, and color are articulated manually in the same form. The only difference are the mouthings Butter, Marmelade and Farbe.
butter – jam – color
Furthermore, mouthings play a role within hypernym and hyponym relations, e.g. bird – blackbird. (iii) Additional information may be expressed by mouthings, e.g. a signed noun combined with a mouthing as an adjective. These functions show that mouthings and signs are characterized by a productive dynamic relationship.
bird – blackbird