Certainly inroads have been made in the area of phonetic description from the classical approaches of the late l9c and the early 20c to the exciting developments of today when we may be finally cracking the problem of the motor control of speaking. Inroads have likewise been made into phonological and syntactic theory, but it seems, even to those engaged in the development of phonetic theory, that in these areas the recent contributions have been somehow more productive. The principal difficulty lies in the form of the projected phonetic theory itself and the extreme opposing nature of the input and output constraints which must be applied to the resulting model. The theory has as its function the relating of linguistic descriptions with the facts of speech and it is patently obvious that linguistic descriptions with respect to their abstraction in formulation are by and large incompatible with the facts of speech. The solution to the problem of establishing phonetic theory hinges on the breaking of the incompatibility.
Linguistic descriptions are of course highly abstract even at the phonological level.
Notice that we could put abstract syntax and phonology of the kind we have now into the same undesirable position of phonetic theory by requiring that it relate itself directly and explicitly to actual observed neural functioning. We can go even further than this. The phonetic component itself converts linguistic knowledge of the structure of the speech act into time-varying commands suitable for the control of the articulatory musculature. It then relates the resulting articulations which are accessible to instrumental investigation to soundwaves which are also accessible to instrumental investigation. The accepting, though, of this highly abstract input derived from present-day phonologies which have not even yet attempted with any measurable success to constrain themselves with neurological considerations is itself highly dubious.