Edward L. Goshorn
Dept. of Speech, Box 3165, Tech Sta., Louisiana Tech. Univ., Ruston, LA 71272
Vincent W. Byers
LSU Med. Ctr., New Orleans, LA 70112
A distinctive feature-based system [W. A. Wicklegren, J. Acoust. Soc. Am. 39, 388--398 (1966)] for scoring errant responses to rhyme test words was developed. Words were presented in noise (0, 4, 8, and 12 dB signal-to-noise ratio) at four intensities (20, 40, 60, and 80 dB HL) to five normal hearing subjects. Errant responses were assigned values from 1 to 7, and categorized as mild, moderate, or severe, according to number of features missed. A basic computer program analyzed responses and yielded a total feature error score (TFES), the number of mild, moderate, and severe errors, and a transformed percentage correct score in rationalized arcsine units (rau) for each 50-item list. The TFES and rau data yielded parallel functions for signal-to-noise ratio and intensity. The correlation coefficient for TFES and rau was -0.965. An ANOVA for rau yielded three significant two-way interactions, the TFES only one. As conditions became difficult and percentage correct diminished, listeners tended to make more mild errors rather than severe. Results have implications for development of word recognition tests.