Cortical Deafness, Auditory Agnosia, and Word-Deafness: How Distinct are They?

Word-deafness (verbal auditory agnosia, agnosia for speech, agnosia for acoustic language) is the most devastating of all the disorders of the central auditory pathway in children, whether the disorder is present from infancy (dysphasia) or is acquired (aphasia). Typically, word-deaf children are mute and understand little or nothing of what is said to them; they resemble deaf children in this respect, except that it is their brains that are abnormal rather than their ears. Judging from personal experience and from the literature, there are many more word-deaf children than adults. The literature on adults consists entirely of isolated case reports. While there are now over a hundred descriptions of children with so-called epileptic aphasia, these have been summarized in several recent reports (e.g., Holmes, McKeever, & Saunders, 1981; Dugas et al., 1982; Dulac, Billard, & Arthuis, 1983; Aicardi, in press). Epileptic aphasia produces the most dramatic form of worddeafness in the pediatric age-group, yet it may not be the most frequent since there are no data on the prevalence of word-deafness among autistic and congenitally dysphasic children. The ability to hear, process, and comprehend speech is indispensable for normal language acquisition. Sustained speech input is also required for the maintenance of speech during the preschool years. Most congenitally deaf children fail to acquire speech (and language) unless educated through the visual channel; the same is true of word-deaf infants. Preschool children who are deafened suddenly by meningitis become mute immediately or within days; so do preschool children with acute epileptic aphasia. Abrupt onset of deafness or word-deafness may result in a dramatic decrease in verbal output, even in older children, despite the advantage provided by better practiced speech and by a sparing of the ability to process language through the visual modality (reading and writing). Adolescents and adults with acquired deafness do not lose their speech, although its acoustic properties will eventually deteriorate somewhat through lack of feedback. Word-deaf adults speak but complain that they don't know what they are saying. There is controversy as to whether word-deafness, in both its developmental and acquired forms, should be