The Connected Speech Test version 3: audiovisual administration

The Connected Speech Test (CST) is used to measure the intelligibility of everyday speech; it is intended primarily for quantifying hearing aid benefit. The test consists of 48 passages of conversationally produced connected speech, each passage concerning a familiar topic and comprising 10 sentences. Listeners are apprised of the passage topic in advance and are required to repeat the sentences one at a time. Each passage contains 25 scoring words. The test is recorded audiovisually. In previous papers, we have reported the development of the test materials and investigations of the use of the audio portion with normally hearing and hearing-impaired listeners. Audio versions of the test have been developed for use with normal hearers (CST version 1), and for hearing-impaired listeners (CST version 2). In the present paper, we report a study of the test administered audiovisually. Twenty-six normally hearing subjects responded to audiovisual presentation of all 48 test passages. On the basis of the results, a new version of the test (CST version 3) was generated. In this new version, the test passages are presented in designated sets of four or six passages. The critical difference between two scores is estimated to be the same for both audio and audiovisual administration.