[Elaboration of a hearing disability scale].

On the basis of a previous pilot study a multiple-choice questionnaire about hearing disabilities was developed. The questionnaire (SDU) allowed 20 items. The answers were tailored to the single question and scaled in increasingly order of disability (form A) or in random order (form B). Modalities of administration (self-report or interview) and form (A or B) were randomized in a group of 123 adult subjects with different degree of hearing impairment. Only one factor, attributable to hearing disability, was extracted by a factor analysis. This factor explains a major variance ratio of items related to speech perception in difficult listening context. A good correlation (r = .74) was found between SDU total score and hearing threshold in the better ear. No difference in mean score, variance and time of reduction of the SDU was found between form A and B. The Authors so propose the use of form A because of a more easy compute of the total score. Self-report was more time-consuming respect to interview (11.7' vs. 8.4'). Furthermore, self-report was non possible in 13.8% of subjects for severe virus impairment and illiteracy and in 6.1% some form of support was necessary. No difference of mean score and variance between self-report and interview was found. SDU represents a tool for hearing disability evaluation useful in aural rehabilitation protocols. The principal advantage is high applicability thanks to short time required, simplicity of task and flexibility in the modality of administration.