In 46 adults with sensory hearing disorder of over ten years' duration, test results of their speech discrimination were analysed and following points were discussed.
1) From the data of speech training in the deaf children, Kubota and others reported that their development of the vowel /i/ articulation is mostly disturbed in vowels and their consonant /r/ articulation developed poorer than /b/, /d/, /g/. While, in the present study, it was shown that deaf adults discriminate the vowel /i/ easily than other vowels, and the consonant /r/ than /b/, /d/, /g/.
From their discrepancy it was assumed that the developmental disturbance of both /i/ and /r/ articulation in the deaf child does not depend on hearing oss, but on the difficulty of /i/ and /r/ pronunciation.
2) The patients with the same discrimination scores were divided in two groups, i.e., patients with high tone loss and with flat audiogram.
In the vowels' discrimination, the latter showed poorer results than the former, and the oposite relation was observed in the consonants' discrimination.
3) A mis-heard consonant largely distributes in its group consonants and in this paper it was discussed that value of mis-perception in unrelated consonants should be distinguished from that of the confusion in its own group.
From this point of view, a new confusion matrix for each case, in which the misperception in related consonants were valued as correct answers, was composed and discrimination scores and transmit information were calculated.
In comparison between the patients with high tone loss and with flat curve, the former shows lower score of transmit information than the latter, even with the same discrimination score.
4) Paired comparison method for speech hearing test was shown. for example: misperception test for /m/, /n/ group.
Eight paired test signals, /m/-/n/, /m/-/k/, /m/-/m/, and /n/-/m/, /n/-/r/, /n/-/k/, /n/-/n/ are given to a subject and the subject is indicated to answer successively whether to speech sound are same or different.
From their answers, the degree of /m/-/n/ confusion, /m/-/n/-/r/, and disability of discrimination of /m/, /n/ group will be known.
