Recognition of word and nonsense syllables in noise

Abstract

In the recognition of human speech, listeners use sensory information from the speech signal as well as signal-independent information, such that acoustic-phonetic salience, lexical status, frequency of usage, and neighborhood density interact in speech recognition. This paper presents detailed results from a replication of a study of context effects reported by Boothroyd and Nittrouer [J. Acoust. Soc. Am. 84, 101–108 (1988)]. 240 phonetically matched word and nonsense CVC syllables at different SNRs were presented to 32 listeners for identification. The results are consistent with the original study, with greater accuracy for words than nonsense items as quantified by a j-factor analysis according to lexical status. Online response collection enabled detailed analyses not reported in the original study. Values for the j-factor according to usage frequency and phonetic confusability are presented. Confusion matrices of the phonemes are presented, and are largely consistent with previous studies for the initial consonants and vowels. Accuracy in the final consonants of nonsense syllables is substantially lower than the corresponding phonemes of words or than the initial consonants of nonsense syllables. Final nasals were particularly difficult to identify.