Development of familiarity-controlled word lists 2003 (FW03) to assess spoken-word intelligibility in Japanese

A new set of ''Familiarity-controlled word lists 2003'' (FW03) has been developed for a spoken-word intelligibility test in Japanese. FW03 consists of 20 lists of 50 words in four word-familiarity ranks (i.e., 4000 words in total). The entropy of (a) initial moras and (b) sequences consisting of a vowel and a following consonant was maximized in the word lists within each word-familiarity rank. FW03 is now published with speech files of the 4000 words spoken by two male and two female Japanese. The word intelligibility of FW03 was measured with the speech files at various signal-to-noise ratios. In addition to the signal-to-noise ratio effects, strong word-familiarity effects were observed in terms of word intelligibility, indicating that word familiarity is well controlled in FW03. FW03 enables us to measure word intelligibility in several word-familiarity ranks that correspond to the degree of lexical information.