Rhetorical criticism: Wrong medium?

Rhetorical criticism (i.e., textual analysis of speeches) is severely handicapped because speech cannot be adequately represented in writing; even if it could be so represented, it is illogical and presumptuous to study critically oral communication received from an inappropriate medium (printed page) via an inappropriate sensory channel (vision). A hierarchy of research priorities—the criterion for relative worth being the degree to which methodologies extend our knowledge of rhetorical theory—is proposed by the author.