Development of a test of speech intelligibility in noise using sentence materials with controlled word predictability

This paper describes a test of everyday speech reception, in which a listener’s utilization of the linguistic‐situational information of speech is assessed, and is compared with the utilization of acoustic‐phonetic information. The test items are sentences which are presented in babble‐type noise, and the listener response is the final word in the sentence (the key word) which is always a monosyllabic noun. Two types of sentences are used: high‐predictability items for which the key word is somewhat predictable from the context, and low‐predictability items for which the final word cannot be predicted from the context. Both types are included in several 50‐item forms of the test, which are balanced for intelligibility, key‐word familiarity and predictability, phonetic content, and length. Performance of normally hearing listeners for various signal‐to‐noise ratios shows significantly different functions for low‐ and high‐predictability items. The potential applications of this test, particularly in the assessment of speech reception in the hearing impaired, are discussed.