Evaluation of Response Times on a Touch Screen Using Stereo Panned Speech Command Auditory Feedback

User interfaces to access mobile and handheld devices usually incorporate touch screens. Fast user responses are in general not critical, however, some applications require fast and accurate reactions from users. Errors and response times depend on many factors such as the user's abilities, feedback types and latencies from the device, sizes of the buttons to press, etc. We conducted an experiment with 17 subjects to test response time and accuracy to different kinds of speech-based auditory stimuli over headphones. Speech signals were spatialized based on stereo amplitude panning. Results show significantly better response times for 3 directions than for 5, as well as for native language compared to English, and more accurate judgements based on the meaning of the speech sounds rather than their direction.