Identification of steady-state vowels synthesized from the Peterson and Barney measurements.

The purpose of this study was to determine how well listeners can identify vowels based exclusively on static spectral cues. This was done by asking listeners to identify steady-state synthesized versions of 1520 vowels (76 talkers x 10 vowels x 2 repetitions) using Peterson and Barney's measured values of F0 and F1-F3 [J. Acoust. Soc. Am. 24, 175-184 (1952)]. The values for all control parameters remained constant throughout the 300-ms duration of each stimulus. A second set of 1520 signals was identical to these stimuli except that a falling pitch contour was used. The identification error rate for the flat-formant, flat-pitch signals was 27.3%, several times greater than the 5.6% error rate shown by Peterson and Barney's listeners. The introduction of a falling pitch contour resulted in a small but statistically reliable reduction in the error rate. The implications of these results for interpreting pattern recognition studies using the Peterson and Barney database are discussed. Results are also discussed in relation to the role of dynamic cues in vowel identification.