Training non-native speech contrasts in adults: Acquisition of the English /ᶞ/-/θ/ contrast by francophones

Abstract

Speech perception abilities are modified by linguistic experience to maximize sensitivity to acoustic contrasts that are important for one's linguistic community, while reducing sensitivity to other acoustic cues. Although some of these changes may be irreversible, in other cases adults may learn to perceive non-native speech sounds in a linguistically meaningful manner with limited perceptual training. The present study investigates the possibility of using a technique based on perceptual fading to train Canadian francophone adults to distinguish the voiced and voiceless "th" sounds of English: I{eth}/, as in "the," versus Iθ/, as in "theta." Following a pretest to measure identification and discrimination performance with both natural and synthetic speech tokens, 10 subjects were trained using synthetic stimuli. Approximately 90 min of this training improved performance with both natural and synthetic tokens relative to that of untrained control subjects. The results suggest that there is a much higher degree of plasticity in these acoustic/linguistic categories than would be inferred from the normal performance of Canadian francophones who learn English as adults. The nature of the training technique is discussed in relation to other training paradigms. © 1986 Psychonomic Society, Inc.