This research presents 2 experiments that serve as a framework for exploring auditory information processing. The framework is termed polychotic listening or auditory search, and requires a listener to scan multiple simultaneous auditory streams for the appearance of a target word. Subjects' ability to scan between 2 and 6 simultaneous auditory streams of letter and digit names for the name of a target letter was examined using 6 loudspeakers. The main independent variable was auditory load, or the number of active audio streams on a given trial. The main dependent variables were target localization accuracy and reaction time. Results show that as load increased, performance decreased. The performance decrease was evident in reaction time, accuracy, and sensitivity measures. The 2nd study required subjects to practice the same task for 10 sessions, for a total of 1,800 trials. These results show that even with extensive practice, performance was still affected by auditory load. The present results are compared with findings in the visual search literature. Some potential applications of this research for cockpit and automobile warning displays and virtual reality and training systems are described.
['Mark D. Lee']
Multichannel Auditory Search: Toward Understanding Control Processes in Polychotic Auditory Listening