Low data rate and intelligible voice communication in harsh acoustic environments

Military, civil and emergency personnel frequently must talk in harsh noise environments using low data rate narrowband radios. Voice communication at very low data transmission rates is a challenge that has traditionally required sacrificing signal quality for low data rate. Raytheon BBN's low data rate Noise Robust Vocoders solve this problem, as illustrated in the diagram below.

Raytheon BBN's Noise Robust Vocoders produce a clear, highly intelligible speech signal in harsh acoustic noise environments while using a data rate that is three to eight times lower than other state-of-the-art vocoders such as the current NATO-standard 2400 bps MELPe vocoder.

Superior Performance in Harsh Environments
Raytheon BBN’s proprietary technology reduces the required bandwidth and, as a result, enhances security by making the transmission less detectable. Our 300 bps and 800 bps Noise Robust Vocoder (NRV) systems deliver intelligibility performance (as measured by the ANSI-standard Diagnostic Rhyme Test, or DRT) that is superior to that of the NATO-standard 2400 bps MELPe vocoder in a variety of harsh noise environments, including:

  • UH-60 Black Hawk Helicopter
  • M577 Armored Personnel Carrier
  • M1 Abrams Tank


Both our 300 bps and our 800 bps NRVs outperform the standard vocoder in harsh noise environments.

Vocoder Comparsion | Listen: Male talker in UH-60 Black Hawk Helicopter noise environment (113 dBC SPL)

Better Communications for Voice Radios
Raytheon BBN’s Noise Robust Vocoders provide significant improvement in intelligibility, capacity, ease of deployment, and security for three broad classes of voice radio communication systems:

  • SATCOM radios
  • HF radios for long range OTH comms
  • VHF/UHF radios for shorter range LOS comms