Misperceptions of spoken words: data from a random sample of American English words

This study reports a detailed analysis of incorrect responses from an open-set spoken word recognition experiment of 1428 words designed to be a random sample of the entire American English lexicon. The stimuli were presented in six-talker babble to 192 young, normal-hearing listeners at three signal-to-noise ratios (0, +5, and +10 dB). The results revealed several patterns: (1) errors tended to have a higher frequency of occurrence than did the corresponding target word, and frequency of occurrence of error responses was significantly correlated with target frequency of occurrence; (2) incorrect responses were close to the target words in terms of number of phonemes and syllables but had a mean edit distance of 3; (3) for syllables, substitutions were much more frequent than either deletions or additions; for phonemes, deletions were slightly more frequent than substitutions; both were more frequent than additions; and (4) for errors involving just a single segment, substitutions were more frequent than either deletions or additions. The raw data are being made available to other researchers as supplementary material to form the beginnings of a database of speech errors collected under controlled laboratory conditions.