Verbal collision avoidance messages during simulated driving: perceived urgency, alerting effectiveness and annoyance

Area of Science:

• Human-Computer Interaction
• Auditory Display Design
• Cognitive Psychology

Background:

• Effective alarm response hinges on aligning perceived alert urgency with actual hazard levels.
• Collision avoidance systems (CAS) require carefully designed auditory alerts for optimal driver interaction.
• Understanding how acoustic and semantic factors influence alert perception is crucial for safety systems.

Purpose of the Study:

• To investigate the impact of acoustic and semantic parameters on perceived urgency, annoyance, and effectiveness of CAS alerts.
• To determine how these parameters influence alarm response speed in a simulated driving environment.
• To inform the design of auditory alarms for improved hazard matching.

Main Methods:

• Two experiments were conducted using a simulated driving context.
• Participants rated and responded to collision avoidance system (CAS) messages presented with varying acoustic intensities (dB S/N ratio) and semantic content.
• Voice gender (male/female) was also a factor in the experiments.

Main Results:

• Increased acoustic intensity (from -2 dB to +10 dB S/N) led to higher perceived urgency and faster response times, alongside increased annoyance.
• CAS semantic content interacted with alarm intensity, with drivers attending more to semantics at lower intensities.
• Both acoustic and semantic parameters independently and interactively influenced CAS alert perceptions under divided attention.

Conclusions:

• Auditory alarm design for CAS can leverage both acoustic intensity and semantic content to create a range of urgency levels.
• Tailoring verbal warnings to specific hazards may enhance hazard-matching capabilities without significantly increasing annoyance.
• Findings provide valuable insights for designing more effective auditory alarms in safety-critical systems.