Sonim Introduces Stone Mountain Remote Speaker Microphones with DSP Noise Cancellation and PTT-over-Cellular Solution

Austin, Texas (March 18, 2021) Sonim Technologies™ (Nasdaq: SONM) announced today the availability of the Stone Mountain Epic Remote Speaker Microphone (RSM) series as part of its rugged mobility accessory product line. The Epic RSM Series with ProClearTM Digital Signal Processing (DSP) noise cancellation is compatible with the Sonim XP8 and XP5s rugged phones. These RSM’s, when combined with the Sonim handsets and PTT-over-Cellular service, provide DSP noise cancellation for clear audio even in the noisiest environments.

“Sonim handsets are known for high noise cancellation and ultra-loud audio features, which provide some of the best audio quality on the market,” said John Graff, CMO, Sonim Technologies. “Stone Mountain has raised the bar in enhanced noise cancellation, making this solution a clear choice for those who require high quality audio in loud, demanding work environments.”

Stone Mountain and Sonim collaborated with a mining client to develop a mission critical communications solution that would perform well in high noise and dust environments. Stone Mountain’s product development efforts with the client resulted in the cutting edge digital signal processing that is incorporated into Sonim compatible Epic RSMs.

Stone Mountain Epic RSMs and Sonim’s XP8 and XP5s handsets include the following key features:

  • Sonim’s SecureAudio interface lets the speaker microphone be physically secured to and powered by the XP8/XP5s, a capability unique to Sonim devices.
  • The RSMs allow users to directly change channels or talk groups and control volume.
  • The RSMs meet Sonim’s ultra-rugged, IP-68 and Mil-Std-810G performance standards.
  • The RSMs include an optional physical knob to change channels, RampClikTM one-touch volume control, listen-only headset jack and large PTT button. The optional listen-only earpiece jack allows for covert listening in secure, quiet settings.
  • A built-in emergency button on the RSM is mapped to the Sonim handset emergency button making it easy to initiate lone worker or man-down alerts.
  • The solution is compatible with Sonim SOS, a powerful app connected to an easy-to-use alarm key that offers an array of safety-first options found only on Sonim devices.

Stone Mountain provides a 2-year limited liability warranty. To see the Stone Mountain Epic RSM in action, click here.

The solution is available via leading mobile operators in the U.S. and Canada. For more information, visit Sonim Accessories.


About Sonim

Sonim Technologies is a leading U.S. provider of ultra-rugged mobility solutions designed specifically for task workers physically engaged in their work environments, often in mission-critical roles. The Sonim solution includes ultra-rugged mobile phones, a suite of industrial-grade accessories, and data and workflow applications which are collectively designed to increase worker productivity, communication and safety on the job site. Please visit Follow Sonim on Twitter and LinkedIn.

About Stone Mountain

Stone Mountain is a leader for ultra-high quality, rugged communication products.  A comprehensive line of wired and BluetoothTM speaker microphones, accessories and vehicle kits provide superior LTE and LMR solutions.  Market sectors served include first responder, military, heavy industrial, transportation and commercial.  Stone Mountain products are built and supported with pride in the USA.  Visit us at:

Media Contact

Sue Huss
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