Psychometric properties of the coordinate response measure corpus with various types of background interference.

Abstract

The coordinate response measure (CRM) corpus has gained broad acceptance as a research tool for investigating speech intelligibility in background competition and has been widely used in studies of informational masking. Beneficial properties of the CRM include closed set format, limited linguistic content, and inclusion of target items that promote sound stream segregation based on the voice-identify of the target talker. Extensive research has demonstrated the psychometric characteristics of CRM target-word identification in the presence of one, two, or three competing talkers from the same corpus as well as long-term speech-shaped noise (LTSSN). Percent correct identification varies non-monotonically with signal-to-background ratio for one and two CRM-talker interference and is monotonic when the number of talkers exceeds 2 or is LTSSN. The CRM has even broader applicability when used with other types of background competition. The purpose of this study is to establish the psychometric characteristics of CRM target-word identification in various backgrounds with the goal of being able to determine when it is appropriate or not to use adaptive threshold procedures with the CRM corpus. Psychometric functions and thresholds based on adaptive tracking for identification of CRM target words presented in multi-talker babble and cafeteria noise will be discussed.