Comprehension of natural and synthetic speech
James V. Ralston, John W. Mullennix, Scott E. Lively, Beth G. Greene, David B. Pisoni · The Journal of the Acoustical Society of America · 1989
Previous studies comparing the comprehension of natural and synthetic speech passages have produced conflicting results. All of these studies used successive measurement techniques in which subjects' comprehension was assessed after the presentation of a passage. However, comparative studies have found that successive methods are less sensitive than simultaneous “on-line” measures. Successive measures are also known to be influenced by memory factors. Subjects in the present experiment monitored for word targets while they listened to short passages and then verified statements after each passage. Both monitoring and verification performance for passages of synthetic speech were depressed relative to passages of natural speech. There was a significant interaction between voice and text difficulty in the monitoring latency data, suggesting that both factors affect mechanisms drawing from the same limited processing resources. Finally, there was a significant interaction between voice and sentence type in the verification task. Subjects listening to passages of synthetic speech had relatively poor memory for propositional information compared to surface (word) information. Taken together, the results indicate that comprehension of synthetic speech is poorer and slower than natural speech. Memory for propositional information extracted from passages of synthetic speech is particularly poor. [Work supported by NSF.]