The NTT Communication Science Basic Research Laboratory is preparing to evolve audio quality with its BRAVE signal processing technology.

The company's new Bit-error Robust-low-delay Audio and Voice Encoding-based product is a 15-channel high-quality 800MHz band wireless microphone system. At the core of BRAVE is its ability to reduce bitrate while still ensuring impeccable sound quality. This is particularly necessary in environments such as office buildings, universities, and rental conference rooms, where several wireless microphones operating closely together would previously face challenges like channel shortages, interference, and potential information leaks. With BRAVE, however, these issues are addressed. The number of simultaneous channels has been increased from the conventional 10 channels to 15, which not only widens the application possibilities but also minimizes the audio delays frequently experienced, ensuring the audio quality remains top-notch.

With its ability to ensure high audio quality while reducing bitrate, BRAVE offers a number of exciting potential uses. They include:

For inter-device audio transmissions, such as those in wireless microphones, real-time processing is vital. Until now, the challenge in making this possible has been how to enhance compression efficiency under these conditions. Doing so means accommodating more microphones in a single space. Often, these transmissions can face errors in the encoded data, and efficient codecs are essential to mitigate decoding errors, especially under low-delay scenarios. Addressing these complexities, BRAVE employs a bit rearrangement technique. This lowers the errors' impact while compressing data effectively, allowing BRAVE to rapidly compress speech and audio data while also being resilient against bit errors.

Transmissions can sometimes face errors. Many codecs use packets to protect their codes. However, packets come with frame-wise headers, which become cumbersome in low-delay conditions. BRAVE's pioneering approach deals with errors without resorting to packets. In conventional bit assignments, errors could introduce significant noise; BRAVE's unique bit assignment ensures that even when errors occur within a frame, the most significant bits remain accurate.

A testament to its innovation and potential, BRAVE was recently honored with the 30th Technical Development Award by the Japan Acoustical Society. This award recognizes groundbreaking advancements in acoustic engineering technology.

NTT--Innovating the Future of Sound