Michigan State University Center for Language Education and Research
Abstract
This paper investigates learner response to a novel kind of intonation feedback generated from speech analysis. Instead of displays of pitch curves, the feedback our system produces is flashing lights of different colors, which show how much pitch variation the speaker has produced rather than an absolute measure of frequency. The variable used to generate the feedback is the standard deviation of fundamental frequency (as measured in semitones) over the previous ten seconds of speech. Flat or monotone speech causes the system to show yellow lights, while more expressive speech that has used pitch to give focus to any part of an utterance generates green lights. The system is designed to be used with free, rather than modeled, speech. Participants in the study were 14 Chinese-native students of English at intermediate and advanced levels. A group that received feedback was compared with a group that received no feedback other than the ability to listen to recordings of their speech, with the hypothesis that the feedback would stimulate the development of a speaking style that used more pitch variation. Pitch variation was measured at four stages of our study: in a baseline oral presentation; for the first and second halves of roughly three hours of training; and finally in the production of a new oral presentation. Both groups increased their pitch variation with training, and the effect lasted after the training had ended. The test group showed a significantly higher increase than the control group, indicating that the feedback is effective. These positive results imply that the feedback could be beneficially used in a system for practicing oral presentations
