We made follow-up studies of 123 patients who received speech therapy at the Speech-Rehabilitation Clinic, Izu-Nirayama Rehabilitation Hospital. The data concerning the conditions of rehabilitation were collected from 90 patients. The recovery processes of 68 aphasic patients about whom we had sufficient data, including the results of psychological and language tests, were also evaluated in terms of the seven-scale-assessment which was devised for trial at our clinic. From our analyses we report the following results: (1) Severe and mild aphasics who were impaired in expression more severely than in reception showed relatively good prognosis. We concluded that speech therapy is significantly effective for them. (2) Good prognosis was not recognized among following types of aphasics. (a) Those who were impaired in reception more severely than in expression. (b) Those who were severely impaired in both. (c) Those who had word-recall difficulties as a main symptom. (3) Mild aphasics showed poor improvement in general. (4) Out of 90 cases, 25.6% obtained jobs after being discharged from the clinic. (5) Vocational rehabilitation was more difficult for the patients who were impaired in reception more severely than in expression and for those who were severely impaired in both. (6) In case of vocational rehabilitation it was effective to employ an assistant, such as a secretary, or to use tools. (7) For the purpose of rehabilitation, not only improvement of speech but adjustment to social and psychological conditions and also to prevocational training were found to be necessary.
It is the purpose in this article to review and evaluate the existing research on delayed auditory feedback (DAF) with respect to: (1) the general effects of DAF on the speech of normal man, (2) DAF-effect on native and foreign languages, and verbal facility, (3) laterality differences, (cerebral dominance) in the auditory feedback control of speech, (4) age-linked changes of auditory feedback monitoring, (5) adaptation to DAF, (6) the speech behavior of stutterers under delayed condition, (7) hearing loss, sex differences and other physiological changes in reaction to DAF. From these studies the following conclusions were drawn. The main effects of DAF is prolongation of vowels. articulatory error and increase in vocal intensity. DAF has smaller effects onn speech when reading difficult than when reading easy passages. The experiment showed the differences between both ears in aural functon during anditory feedback control of speech. The delay time for maximal DAF-effects varies with age. While some degree of adaptation takes place to continued DAF, it is not complete. Under DAF the frequency of stuttering is reduced. It is possible to use DAF as a predictor of hearing threshold test. Sex differences in reaction to DAF are observed.