Forest fire is burning in the hills of suburban Los Angelesjumping from one patch of dry bush to another, approaching a cluster of houses. The landscaping of the first house is on fire, but the house itself stubbornly refuses to catch fire: any small flame that appears along its walls or roof quickly dies out. The water is not visible – the flames are extinguished by sound waves. This type of acoustic fire suppression could soon play a vital role in fighting wildfires.
The key ingredients of fire are heat, fuel and oxygen; remove one of them and the flame goes out. Sound waves can extinguish a fire by pushing oxygen molecules away from the fuel, preventing the fire from receiving the air it needs to continue the combustion reaction.
Jeff Bruder, an aerospace engineer who researched thermal energy conversion at NASA, co-founded Sonic Fire Technique build a sound-generating machine for this purpose. “Essentially, the oxygen vibrates faster than the fuel can use it, so you block the chemical reaction,” Bruder says. The company has demonstrated extinguishing fires up to 25 feet away.
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Using sound waves to extinguish fires is not a new concept. US Defense Advanced Research Projects Agency studied the method from 2008 to 2011and academic researchers studied the technique over the next decade (including a team at George Mason University that built a fire extinguisher similar to subwoofer in 2015).
“Acoustic effects on flames are well known in combustion,” says Albert Simeoni, chair of the fire protection department at Worcester Polytechnic Institute in Massachusetts. “The challenge is to scale up the technology without creating interference or even harmful sound effects.”
Sonic solves this problem by using infrasound. While previous attempts used sound waves in the 30 to 60 hertz range, which can be created with simpler equipment, Sonic remains at 20 hertz or lower. These waves are inaudible to humans and travel further than higher frequency waves.
Homes often catch fire because embers accumulate in adjacent foliage or get caught in attic vents, Bruder said. Sonic's system uses a piston pulsating from an electric motor to create sound waves that travel through metal ducts installed on the building's roof and under its eaves. The system is automatically activated when sensors detect a fire, creating a kind of infrasound force field to extinguish it and prevent a new fire.
Acoustic waves can have a powerful effect on a fire, but they only affect small flames, says Arnaud Trouvé, chair of the fire protection department at the University of Maryland. However, homeowners and utilities are willing to give it a try: Sonic is working with two California utilities to demonstrate its technology. Homeowners have also signed contracts with the company, which plans to conduct 50 pilot installations in early 2026.
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