Age-Related Physical and Emotional Characteristics to Safety Warning Sounds: Design Guidelines for Intelligent Vehicles

Recent technological advances have made motor vehicles more intelligent to increase safety and comfort. An intelligent vehicle provides drivers with safety warning information through audible sounds, visual displays, and tactile feedback. However, elderly drivers often have decreased cognitive and psychomotor abilities in the areas such as hearing, eyesight, short-term memory, and spatial perception. Therefore, possible age-related deficits should be considered when designing effective warning systems. This paper evaluates the impact of advancing age on drivers´ physical responses and emotional preferences with regard to audible safety warnings that are widely used to warn about driving hazards. Three sound characteristics (frequency, tempo, and intensity) and three age groups (younger, middle, and older) were considered in investigating the effect of age-related hearing loss and reduced speed of movement. Data were collected from 38 drivers who drove on a simulated rural road in a driving simulator. Experimental results showed that age influenced drivers´ responses and emotional preference. An appropriate range of warning sounds is suggested.