Hara Keiko

日本語母語話者におけるディスレクシアの問題を概観する

日本言語聴覚士協会正会員10773名を対象として、小児構音障害への対応に関するアンケート調査を実施した。その結果、有効回答数は183で、回収率は1.7%であった。担当した子どもの41.5%が構音の問題を有しており、年齢別では幼児が66.3%と最も多かった。障害別では、知的障害が22.9%と最多で、機能性構音障害15.8%、広汎性発達障害15.4%、口唇口蓋裂13.6%の順であった。構音の誤りは未熟構音が48.9%と約半数を占めた。対応方法については、構音の改善を目的とし、直接的な構音指導を行った群(直接的指導群)が49.3%と最も多く、摂食指導や言語発達の促進など構音改善を期待した働きかけを行った(改善期待群)が29.0%、対応なし群が21.7%であり、障害別に対応方法をみると、肢体不自由では対応なし群が約半数を占めた。なお、臨床での問題点としては、対応できる施設や指導者の不足、STの訓練技術の問題、合併例への対応の3つに大別された。

This paper presents an argument for the need to develop a battery of tests for assessing phonological awareness of the Japanese language. It has been reported that there are some children with phonological disorders who have a low level of phonological awareness and who might also have reading difficulties. Phonological awareness is the ability to identify the phonological components in a word and manipulate them intentionally. It has been suggested that phonological awareness might underlie the correct articulation of words and sentences because it enables one to identify phonological components, grasp sound sequences, and form internal phonological representations of words and sentences. In addition, the assessment of phonological awareness is indispensable in the diagnosis of dyslexia. The assessment of phonological awareness might also be useful in the case of phonological disorders as well since it would provide important information relating to the underlying mechanism of the disorder and to therapy. Several batteries of tests for assessing phonological awareness of English have been developed and widely used. It thus seems important to develop a battery of tests for assessing phonological awareness of Japanese.

The purpose of this paper is to examine the development of phonological awareness and the relationship between phonological awareness and reading ability in Japanese children. The subjects were 123 preschool children and 98 school children (grades one through three) who were considered to have normal mental, language, auditory, and visual abilities. They were given four phonological awareness and reading tasks. The results were analyzed in terms of correct response rate, score, and reaction time. Based on a 70% achievement criteria for each task, the following points were concluded: 1) phonological awareness tasks were accomplished at different age levels, 2) deletion tasks for three-mora-words and reversal tasks for four-mora-words were achieved by the end of the pre-school period, and 3) deletion tasks for six-mora-words, reversal tasks for four-mora-words, and vowel identification tasks were achieved soon after formal instruction in reading and writing of hiragana. Statistically, a strong correlation was found between deletion ability and reading comprehension ability, as well as between reversal ability and reading comprehension ability. How phonological awareness skills of deletion and reversal tasks facilitate reading are also discussed.