ABSTRACT
One of the major issues that has intrigued linguists is the question of what effect the
modality of perception/production has on the grammar of a language. If the grammar is
viewed as composed of several components or modules, in which components would
modality effects be observed? Is the modality difference between speech and sign
reflected only in the nature of the phonetic features that map into production and
perception? Or, given the substantial differences in the physics of speech and sign, might
there not be higher level organizational differences between the two linguistic modalities,
and if so, what and where? As a result of extensive discussion on this issue, Ed Klima,
Ursula Bellugi, and I presented the concept of “layering” in an article that documented
the phonological separation of sign components for morphological purposes (Wilbur,
Klima, & Bellugi, 1983).
