Watch Duty has introduced a new audio alert developed with Sixième Son to warn users of threats to life or property from wildfires in the US.
The alert was announced on Monday 3 November 2025 from San Francisco and New York, US, for its real-time wildfire alerts app that now reaches more than 15 million active users across 22 states in the Northwest, Southwest and Central regions.
The company said the partnership focused on creating a sound that cuts through everyday device noise without adding to stress during fire-related emergencies.
Watch Duty described the app as a go-to tool for people facing wildfire risk when fast, clear information is needed.
Sixième Son said the audio was designed to carry information quickly in moments of stress, rather than to startle listeners.
Daina Todorovic, Chief Client Officer US at Sixième Son, said: “Sound can carry information more quickly than text or visuals, especially in moments of stress.
“Our goal was not to create frightening sounds, but instead, create clear, firm, and human sonic cues that people instinctively recognize and comprehend.”
Todorovic said the firm applied its sonic identity work to public warning by combining design methodology with empathy to support people as they respond to wildfire alerts.
She added that the resulting soundscape was created to accompany people through fear, preparation and relief as an incident develops.
According to Sixième Son, the alert has an organic quality and takes inspiration from the sound of a drop of water, rather than relying on synthetic tones.
The firm said this sound character was chosen to help the alert stand out on mobile devices while still reassuring users during emergencies.
Sixième Son added that the alert uses distinct tonalities around 1000 Hz, which it noted is close to a human voice frequency and optimized for smartphone speakers.
The company said the alert is intended to address notification fatigue that can cause some mobile phone warnings to be missed or ignored.
Watch Duty reported that its platform reached 7.2 million yearly active users in 2024.
The company said the app community has now grown to more than 15 million active users and spans 22 wildfire-prone US states.
According to Watch Duty, it was named in the 2025 TIME100 Most Influential Companies list.
The firm said it was also ranked as the number one non-governmental organization in 2025 by Fast Company.
During the Palisades and Eaton fires in January 2025, Watch Duty said the app gained 1.4 million new users in 48 hours.
The company reported that the service was widely credited as a lifeline for people in Los Angeles during those incidents.
John Mills, Chief Executive Officer at Watch Duty, said: “Every sound tells a story.”
Mills said the collaboration with Sixième Son was intended to ensure that app users receive information with clarity, humanity and trust.
John Mills, Chief Executive Officer at Watch Duty, added: “These sounds aren’t just alerts, they’re lifelines.”
Watch Duty stated that it plans to introduce a second sound into the app as part of its alerting system.
According to the company, this new tone will be calmer than the primary wildfire alert and will share some of the same sonic character, so users recognize it as related.
Watch Duty said the additional sound will be used when there is still time to prepare for danger, such as during floods or storms.
The firm described this tone as a prompt to remain watchful where conditions create risk but an immediate threat to life or property has not yet developed.
According to Watch Duty, sound is becoming an inclusive and accessible component of public warning as climate change drives more frequent and severe natural disasters.
The organization said audio cues can be heard instantly across language barriers, remain reliable when screens cannot be checked and are strong enough to wake people when needed.
Fire and rescue chiefs and senior officers may review the Watch Duty approach when considering how public-facing alerts reach residents during wildfire seasons and other climate-driven emergencies.
Emergency and disaster response managers can compare the app’s use of distinct tones for immediate threats and preparatory stages with existing siren, wireless alert and app-based systems in their jurisdictions.
For training officers and instructors, the design of a recognizable, human-centered tone around voice-like frequencies offers a case study for exercises that involve public warning, evacuation readiness and communication under stress.
Risk assessors and government departments responsible for hazard communication may examine how a single app has attracted more than 15 million active users across 22 US states, including 1.4 million new users during the Palisades and Eaton fires in January 2025.
These figures show how mobile audio alerts that address notification fatigue can influence how communities receive information about wildfires, floods and storms when rapid awareness is required.
