Word and mora intelligibility in ‘‘Familiarity-controlled word-lists 2003 (FW03).’’
Tadahisa Kondo, Shigeaki Amano, Shuichi Sakamoto, Yôiti Suzuki · The Journal of the Acoustical Society of America · 2006
‘‘Familiarity-controlled Word-lists (FW03)’’ was developed to make it possible to perform intelligibility tests on the same person repeatedly and/or under several different conditions. FW03 consists of 20 lists of 50 words in four word familiarity ranks. These words were selected taking phonetic balance into consideration to maximize their variety of initial moras and vowel-consonant sequences. To confirm that all FW03 word lists from a particular familiarity rank present the same hearing difficulty, we measured the word intelligibility of all the words in FW03. Sixteen subjects listened to 4000 words spoken by four speakers with seven signal-to-noise ratios. The mean intelligibility scores for the lists were significantly different even for the same familiarity rank. The intelligibility was apparently influenced by some specific moras and their position in words. These results suggest that it is difficult to equalize the word intelligibility of the lists even when the word familiarity is controlled more precisely. We therefore examined several methods for equalizing the intelligibility among the lists such as controlling the sound pressure level for each word when operating an actual intelligibility test. The effectiveness of these methods is discussed with detailed analyses of word and mora intelligibility in FW03.