The verbal code may be transmitted on oral, written, or manual (signed)
channels. The relative load carried on each channel depends on its functional
distribution in a particular speech community, and thus they are of differential
importance in the linguistic repertoire of any individual or society.
Full participation in a deaf speech community requires ability to interpret
language on the manual channel but not the oral, for instance; a speech
community with a primarily oral tradition may not require interpretation of
writing; and a speech community which relegates much information flow to
the written channel will require literacy skills for full participation. Thus,
the traditional linguistic description which focuses only on the oral channel will be too narrow to account for communicative competence in most societies.
Although it may cause some terminological confusion, references to
ways of speaking and ethnography of speaking should be understood as usually
including a much broader range of communicative behavior than merely
speech.