Cognitive load measurement from user's linguistic speech features for adaptive interaction design

An adaptive interaction system, which is aware of the user's current cognitive load (CL), can change its response, presentation and flow of interaction material accordingly, to improve user's experience and performance. We present a speech content analysis approach to CL measurement, which employs users' linguistic features of speech to determine their experienced CL level. We show analyses of several linguistic features, extracted from speech of personnel working in computerized incident control rooms and involved in highly complex bushfire management tasks in Australia. We present the results of linguistic features showing significant differences between the speech from the cognitively low load and high load tasks. We also discuss how the method may be used for user interface evaluation and interaction design improvement.