ABSTRACT
This chapter examines the relationship of auditory parameters to perceived urgency by measuring the physiological responses associated with electroencephalogram (EEG) and event- related brain potentials (ERP) data as well as subjective assessments and reaction time. It examines the amplitude differences as a function of manipulating the sound parameters of an auditory warning and the importance of the warning to the task at hand. An ERP represents an average of a number of neurological reactions which are generated in response to specific and brief stimuli, such as a flash of light or a pulse of sound. EEG frequency analysis involves determining the power, or amount of activity, in the theta, alpha and beta frequency bands within an EEG segment. Auditory warnings were originally implemented in aircraft because signal lights were considered to be ineffective, and auditory warnings conserved space on the already crowded panel of the cockpit.
