RESUMO
A variety of auditory warning tones was evaluated to determine generally appropriate intensity levels for presentation in the automobile environment. Twenty-four subjects listened to tones presented at several intensity levels under three background noise conditions recorded in actual vehicles: relatively quiet (35 mile/h (56 km/h), smooth road), relatively loud (55 mile/h (89 km/h), rough road), and radio (35 mile/h (56 km/h), smooth road, and radio broadcast). Data were gathered on the minimum intensity level (in decibels (dB) above the masked threshold (MT) required to achieve a consistent criterion detection rate, as well as the preferred tone intensity level (in dB above the MT) in each background noise condition. The preferred levels were louder than those required to achieve the detection criterion in both the relatively loud and quiet background noise conditions; thus, the preferred levels are the recommended levels under those conditions. This was not the case in the radio condition; therefore, it is recommended that future research efforts evaluate the effects of automatically muting the radio/stereo system when important auditory warning tones are being presented.
RESUMO
This study compared the effects of simulated head-up display (HUD) and dashboard-mounted digital speedometers on key perceptual driving tasks in a simulated driving environment. Subjects were 20 male and female volunteers ranging in age from 19 to 51 years. A videotape, taken from the driver's perspective, of a car traveling along a memorized route served as the test scene. While viewing the test scene subjects performed tasks related to navigation, speed monitoring, and salient cue detection. The simulated HUD speedometer produced generally superior performance on the experimental tasks; most important, it enabled subjects to respond significantly more quickly to the salient cues. Implications for the effects of HUDs on automobile safety are discussed.
