Project Duration
9 Months
Role
Sound user experience, Product design
Sound agency
AudioUX
Sound & Safety Synergy
Audio user experience (2022)
Context
Nauto’s core value lies in leveraging AI-driven insights to improve driver safety and fleet efficiency. By capturing real-time data and analyzing driver behavior, Nauto helps fleets identify risks, coach drivers effectively, and reduce collisions. Central to this mission is the in-cabin experience, where timely and intuitive feedback plays a critical role in shaping behavior. The sound user experience, as a key component of this feedback loop, directly impacts how drivers perceive and respond to alerts. Redesigning this experience ensures that auditory cues are not only effective but also seamlessly integrated into the driving environment, ultimately enhancing safety and reinforcing Nauto’s position as a leader in intelligent fleet management.
Problem
The ultimate vision is to position Nauto as a leader in AI-powered driver behavior fleet management. Central to this goal is driving meaningful change in driver behavior through thoughtful and impactful design. To realize this, we aim to develop a cohesive and strategic soundscape for Nauto, leveraging expertise and guidance from an agency with proven experience in the automotive industry. By adopting a forward-thinking approach to enhancing in-cabin experiences—such as introducing refined alert sounds—we strive to create a more intuitive and effective interface that fosters safer and more efficient driving behaviors.
Descriptive vs Prescriptive
We conducted internal testing with both descriptive and prescriptive alert voiceovers, gathering valuable feedback on user preferences. The prescriptive voiceovers were particularly favored for their personable tone, with users noting that they were less intrusive during repeated playback and provided a more companion-like presence. Following this, we expanded testing with an external customer, where the response was overwhelmingly positive, with notable improvements in driver performance, further validating the effectiveness of the prescriptive approach.
Guiding principles
Through collaborative brainstorming sessions with product managers, cross-functional teams, the head of product, and in-house psychology specialists, we developed the foundational framework for Nauto’s sound language and design principles. This framework was strategically crafted around the concept of risk levels, using these categories as a guiding structure for grouping and organizing auditory cues. This approach ensures that the sound design is both intuitive and contextually aligned with the varying degrees of driving risk, creating a cohesive and effective auditory experience.
Refinement
In collaboration with AudioUX, we refined and advanced our sound design framework by introducing a family-based categorization system. Each alert sound, or earcon, was strategically associated with a specific sound family. This approach minimizes cognitive load on the driver by creating a more cohesive auditory experience, avoiding the confusion of assigning distinct alert sounds to every individual event type.
Attention vs Risk
To effectively categorize events into the appropriate sound families, we analyzed the relationship between the level of attention required from the driver and the corresponding risk level of each event type. This approach ensures that each alert sound is appropriately calibrated to the severity of the situation, providing a more intuitive and contextually relevant auditory experience.
Auditory design standards
Our auditory design standards are informed by key principles that enhance user responsiveness and minimize cognitive load. Voice prompts tend to result in slower reaction times compared to non-verbal cues, so we prioritize simpler sound designs for faster comprehension. Complex tones are processed more quickly than pure tones, while shorter sound durations help reduce cognitive load. Higher frequencies lead to faster reaction times, and shorter sound intervals are perceived as more urgent, effectively signaling immediate attention. Additionally, sounds with quicker attack times in their volume envelope are perceived sooner, further accelerating user response. These standards ensure that auditory cues are both effective and intuitive in guiding user behavior.
Voice design standards
Our voice design standards prioritize clarity and urgency, ensuring that each type of alert is delivered in the most effective manner. Critical alerts should avoid speech messages entirely, while urgent alerts are best conveyed with concise, one-word messages. Cautionary alerts should use 3 to 4 words to maintain clarity without overwhelming the listener. The speech rate should fall between 150-200 words per minute to ensure intelligibility and ease of comprehension. To enhance urgency, higher fundamental frequencies are used in more critical situations, with lower frequencies reserved for less immediate contexts. Additionally, we prefer voice branding over text-to-speech (TTS) to foster a more personalized and consistent auditory experience.
