[Elaboration of the hearing disability scale].

On the basis of a previous pilot study, a multiple-choice questionnaire regarding hearing disabilities was developed. The questionnaire (SDU) was made up of 20 items. The answers were tailored to the single question and scaled according to the increasing degree of disability (form A) or in random order (form B). Administration modality (self-report or interview) and form (A or B) were randomized in a group of 123 adult subjects with different degrees of hearing impairment. Only one factor, attributable to hearing disability, was extracted by 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 necessary scoring time of the SDU was found between form A and B. The Authors thus propose the use of form A because of a more easy computation of the total score. Self-report was more time consuming with respect to interview (11.7' vs. 8.4'). Furthermore, self-report was non possible in 13.8% of subjects for severe sign impairment and illiteracy and in 6.1% some form of support was necessary. No difference in mean score and variance between self-report and interview was found. SDU represent a tool for hearing disability evaluation useful in aural rehabilitation protocols. The principal advantage is high applicability thanks to the short time required, simplicity of task and flexibility of administration modality.