Toward a Better Understanding of In-Vehicle Auditory Warnings and Background Noise

The effectiveness of three types of in-vehicle warnings was assessed in a driving simulator across different noise conditions.

Although there has been much research comparing different types of warnings in auditory displays and interfaces, many of these investigations have been conducted in quiet laboratory environments with little to no consideration of background noise. Furthermore, the suitability of some auditory warning types, such as spearcons, as car warnings has not been investigated.

Two experiments were conducted to assess the effectiveness of three auditory warnings (spearcons, text-to-speech, auditory icons) with different types of background noise while participants performed a simulated driving task.

Our results showed that both the nature of the background noise and the type of auditory warning influenced warning recognition accuracy and reaction time. Spearcons outperformed text-to-speech warnings in relatively quiet environments, such as in the baseline noise condition where no music or talk-radio was played. However, spearcons were not better than text-to-speech warnings with other background noises. Similarly, the effectiveness of auditory icons as warnings fluctuated across background noise, but, overall, auditory icons were the least efficient of the three warning types.

Our results supported that background noise can have an idiosyncratic effect on a warning's effectiveness and illuminated the need for future research into ameliorating the effects of background noise.

This research can be applied to better present warnings based on the anticipated auditory environment in which they will be communicated.