Skip to main content

Your next noise-canceling earbuds may use Navy sonar tech

Two views of the xMEMS Cypress driver.
xMEMS

A company that is pioneering the use of earbud speakers that are manufactured like microchips says it has developed a way to convert inaudible, high-power ultrasound into hi-fi stereo sound, using a single driver. The result is what the company — called xMEMS —  says is a micro-electromechanical system (with a convenient MEMS acronym) driver that’s powerful enough to deliver sound as well as active noise cancellation in a set of wireless earbuds.

According to xMEMS, these MEMS drivers possess a number of advantages for buyers and manufacturers of earbuds, like extreme ruggedness, a huge frequency-response range, ultrafast transient response (the ability to quickly shift from one sound to another), and more accurate sound reproduction.

But because MEMS drivers use tiny silicon membranes to produce the moving air that our ears detect as sound, they suffer from one critical weakness: when used in vented earbuds (most ANC earbuds have vents), they can’t generate the needed sound pressure level (SPL) at lower frequencies that are essential for ANC. For active noise cancellation to be effective, it requires 120 dB SPL at 20Hz, but earbud venting robs the 20Hz frequency of about 20 dB SPL. This means that for any driver to deliver the needed power, it has to produce 140 dB SPL, and current MEMS drivers can only reach 120 dB.

Two xMEMS Cypress drivers seen sitting on a U.S. dime coin for scale.
Two xMEMS Cypress drivers seen sitting on a U.S. dime for scale. xMEMS

Manufacturers that have wanted to make wireless earbuds that use MEMS drivers and provide ANC have had to resort to a dual-hybrid driver design, like Creative’s Aurvana Ace and Aurvana Ace 2. These are the first MEMS-based wireless earbuds, but they use a traditional dynamic driver to generate the needed low-frequency SPL.

xMEMS says its latest MEMS driver, which it calls Cypress, can overcome the traditional SPL limitation and is the first to offer both hi-fi sound and ANC capabilities from a single MEMS driver. To make it work, xMEMS has turned to ultrasound technology that was originally developed by both the U.S. and Soviet navies in the mid-1960s for sonar applications. This original research proved that it was possible to embed human-audible sound information within a beam of inaudible ultrasound.

The Cypress driver is capable of generating high-SPL ultrasound (with human-audible sound modulated into its sound waves) and then routing these ultrasonic waves through a set of valves that effectively filter out the ultrasonic frequencies, leaving normal audible sound in the 20Hz-20kHz range — at the needed 143 dB SPL for ANC to be effective.

While the original sound-from-ultrasound techniques from the 60s proved poor at maintaining acceptable levels of audio fidelity, xMEMS claims the Cypress can deliver sound that is actually more faithful to original recordings than competing speaker technologies.

At the moment, the Cypress is at the working prototype stage, and xMEMS intends to demo the technology to CES attendees in January 2024. The company plans a full production rollout by the end of 2024, which means we could see the first noise-canceling earbuds with Cypress’ ultrasonic technology by early 2025.

Editors' Recommendations

Simon Cohen
Contributing Editor, A/V
Simon Cohen covers a variety of consumer technologies, but has a special interest in audio and video products, like…
Montblanc’s first wireless earbuds get a little help from Axel Grell
Montblanc MTB 03 wireless earbuds inside charging case.

Montblanc, the iconic maker of luxury writing instruments, is expanding its reach into the audio world with its first set of wireless earbuds. The MTB 03 are small and stylish, with active noise cancellation (ANC) and a design that incorporates the company's instantly recognizable glossy black finish and rounded star motifs. They're available starting July 1 at all Montblanc boutiques and Montblanc.com, for 345 British pounds (about $438).

The MTB 03 benefit from the expertise of Axel Grell, the man behind the development of many of Sennheiser's headphones and earbuds. Montblanc says that Grell was responsible for creating the MTB 03's sound signature. This is a consistent pattern for Montblanc, which partnered with Audeze’s founder, Alex Rosson when it began its audio journey with the MTB 01 wireless ANC headphones, which launched in 2020.

Read more
Nura’s personalized earbuds are reborn as the Denon Perl
Denon Perl Pro earbuds.

In April 2023, Denon announced that it had acquired Australian wireless earbud maker, Nura, and that we could expect to see new earbuds from the combined brands "soon." Today, Denon has effectively relaunched Nura's two wireless earbuds -- the NuraTrue and NuraTrue Pro -- as the Denon Perl ($199) and Denon Perl Pro ($349). Denon says a limited number of Denon Perl and Perl Pro headphones are now available for purchase at Denon.com, with a full rollout planned for later this year.

The Perl and Perl Pro, which Denon has stylized with a capital L (PerL), appear to preserve all of the NuraTrue and NuraTrue Pro's features, and in looking at the new Denon earbuds, it appears that they're also physically identical to Nura's now-discontinued products. One thing that has changed is the price of the NuraTrue Pro. Already fairly expensive at $329, Denon's version is now $20 more.

Read more
Anker Soundcore says its new wireless buds will block up to 98% of external noise
Woman wearing Anker Soundcore Liberty 4 NC.

Anker's Soundcore division has got a new set of wireless earbuds. And while the name may sound familiar -- they're called the Liberty 4 NC -- their price is a nice surprise: just $100. That buys you a set of hi-res-capable wireless earbuds that Anker claims have really impressive active noise cancellation (ANC) and battery life.

Anker calls it "Adaptive ANC 2.0" a system that uses two mics -- one inside your ear and one on the outside of the earbuds -- to adapt ANC performance instantly in any environment. The company must be confident that the system works well; it claims it blocks out up to 98.5% of external noise. Not even the superb Apple AirPods Pro 2 claim that kind of performance.

Read more