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The kinetic energy of your voice powers this microphone

This device from Boston-based Vesper converts sound waves to electricity. And it’s coming to voice-activated trash cans.

Vesper’s microphones use kinetic energy from the human voice to turn on. Pictured is its first product, the VM1000. Vesper

That smart speaker in your kitchen doesn’t turn off in between your requests. It has a microphone “listening” for your words, and using enough energy to run a small light bulb around the clock.

Smart speakers have joined the legion of “vampire” devices in our homes — televisions, cable boxes, game players, and more, continuously drawing power so they’re ready when we want them. These use up to 10 percent of the power in a typical US household, a total that will increase as voice becomes a remote control for everything from microwaves to window blinds.

Enter Vesper, a startup in Downtown Crossing. The company makes microphones that run on sound waves — when you give a command to a product equipped with a Vesper mic, the kinetic energy of your voice vibrating the air turns on the microphone. “We’re turning the microphone into an on switch,” says Matt Crowley, chief executive of four-year-old Vesper.

Vesper’s three products use piezoelectric crystals, which generate electricity when they move. While piezoelectronics aren’t new, the particular technology advance that allows for a voice-activated microphone was developed in the University of Michigan lab of Karl Grosh, who cofounded the company with his former student Bobby Littrell, Vesper’s chief technology officer. The company has raised $43 million in funding from Cambridge venture capital firm Accomplice, Bose, Amazon, and others. Its products are already in home speakers from Linkplay Technology, which uses Amazon’s Alexa Voice Service, and Crowley says Vesper is in active collaborations with Amazon.


Besides saving power, piezoelectric microphones also should be more durable than many traditional devices, which capture sound using plates that can become clogged by water, dust, and grime. Vesper’s microphones still work even after being dropped into beer. Crowley says durability will matter more as voice-control spreads into things like cars, where components need to last as long as 10 years.


Wireless headset makers are also working with the company. But the next place you might encounter one of its products is far less glamorous: simplehuman, which makes home organization products, will include Vesper microphones in a voice-activated trash can due out later this year. A basic model will cost $200, and use voice commands to open or close.

The miniature microphone market is projected to exceed $1 billion in 2018, though each Vesper mic sells for between 50 cents and $1. But some people may pause, concerned about companies eavesdropping on their conversations. Crowley says many voice-activated devices, such as trash cans, won’t connect to the Internet, and that Vesper generally works with companies that allow consumers to turn off voice activation.

“Every technology could be used for good or bad,” Crowley says, so consumers need to stay vigilant. At least when we use Vesper’s products, we know we’re killing some power-sucking vampires.

Vesper microphones, by the numbers

Price: Less than $1

Materials used: Aluminum, nitrogen, silicon, gold

Range: 15 meters

Andy Rosen is a Boston Globe staff writer. Send comments to magazine@globe.com. Get the best of the magazine’s award-winning stories and features right in your e-mail inbox every Sunday. Sign up here.