Lack of a coherent theory limits the diagnosis and prognostic value of the central auditory processing disorder

Abstract

Spanning almost 6 decades, CAPD, defined as a modality specific perceptual dysfunction not due to peripheral hearing loss, still remains controversial and requires further development if it is to become a useful clinical entity. Early attempts to quantify the effects of central auditory nervous system lesions based on the use of filtered-speech material, dichotic presentation of digits, and various non-speech tests have generally been abandoned due to lack-of-success. Site-of-lesion approaches have given way to functional considerations whereby attempts to understand underlying processes, improve specificity-of-diagnosis, and delineate modality-specific (auditory) disorders from “non-specific supramodal dysfunctions” like those related to attention and memory have begun to fill the gap. Furthermore, because previous work was generally limited to auditory tasks alone, functional dissociations could not be established and consequently, the need to show the modality-specific nature of the observed deficits has been compromised; further limiting progress in this area. When viewed as a whole, including information from consensus conferences, organizational guidelines, representative studies, etc., what is conspicuously absent is a well-defined theory that permeates all areas of this domain, including the neural substrates of auditory processing. We will discuss the implications of this shortcoming and propose ways to move forward in a meaningful manner.