Designing Speech Displays for Telephone Information Systems

Abstract

This study used a computer-driven telephone information system as a real-time human-computer interface to simulate applications where synthetic speech is used to access data. Subjects used a telephone keypad to search though an automated department store database to locate and transcribe specific information messages. Because speech provides a sequential and transient information display, users may have difficulty navigating through auditory databases. One issue investigated in this study was whether the alternate use of male and female voices to code different levels of the database would improve user search performance. Other issues investigated were the basic intelligibility of these male and female voices as influenced by different levels of speech rate. All factors were assessed as functions of search or transcription task performance and user preference. Analysis of transcription accuracy, user search efficiency and time, and subjective ratings revealed an overall significant effect of speech rate on all groups of measures but no significant effects for voice type or coding scheme. Results were used to recommend design guidelines for developing speech displays for telephone information systems.