Comparability of signed and spoken languages: Absolute and relative modality effects in cross-modal typology

Abstract This article sets out a conceptual framework and typology of modality effects in the comparison of signed and spoken languages. This is essential for a theory of cross-modal typology. We distinguish between relative modality effects, where a linguistic structure is markedly more common in one modality than in the other, and absolute modality effects, where a structure does not occur in one of the modalities at all. Using examples from a wide variety of sign languages, we discuss examples at the levels of phonology, morphology (including numerals, negation, and aspect) and semantics. At the phonological level, the issue of iconically motivated sub-lexical components in signs, and parallels with sound symbolism in spoken languages, is particularly pertinent. Sensory perception metaphors serve as an example for semantic comparison across modalities. Advocating an inductive approach to cross-modal comparison, we discuss analytical challenges in defining what is comparable across the signed and spoken modalities, and in carrying out such comparisons in a rigorous and empirically substantiated way.