Abstract
The use of sensitized verbal tests in the diagnosis of central deafness is critically reviewed.
The concept of intrinsic (neural) redundancy is the main point in the operational model; different modalities of coupling between intrinsic and extrinsic redundancy bring forth different patterns of intelligibility.
The age of the subject thus becomes critical; on the contrary, the influence of the IQ can be minimized by carefully selecting the tests.
These can be divided into monaural and dichotic; among the latter, only the tests involving competing information are of value, whilst the so-called summation tests should now be disregarded.
The clinical results are only briefly quoted, since they are well-known. The contribution to the advances in neurophysiology seems to be more interesting.
The influence of reticular formation on auditory stimulation, the crossing of the auditory pathways, the existence of a secondary auditory area have been psychoacoustically confirmed by the use of the monaural tests.
In their turn, the dichotic competing message tests have enabled a beautiful model of language perception to be drawn, and have definitely demonstrated the so-called hemispheric specialization (or dominance) for verbal and nonverbal messages.