Another
reason to incorporate more than one sense into a design display
is to compensate for a sensory channel that is likely to be adversely
impacted by the environment or impaired by the state of the user.
An additional sense modality is employed to alert the user.
A
sense modality may become non-available for use because of:
Environmental
constraints
- Vision can be hampered by fog, heavy rain, sleet, snow, or darkness.A noisy environment may preclude the use of auditory
alarms. Tactile signals may not be practical or possible for the
application. Olfactory signals may be masked by other smells.
Sensory
impairment - The state of the user may require additional
sense modalities for displays. It may be necessary to arouse the
user from sleep, drowsiness, or when vigilance is low from boredom.
Rumble strips effectively use sound (auditory) and vibration
(tactile) to alert drivers that they have strayed off the
main highway surface and onto the shoulder. (DOT
film)
