Alexa makes it possible for customers to conveniently and intuitively control devices from a distance using just their voice. Today, the most prevalent Alexa-enabled products are table-top that sit on a surface in the room. In the future, device makers will take a more seamless approach, moving voice control to the edges of the room by integrating the Alexa Voice Service (AVS) into slim profile and wall-mounted devices.

Shifting voice-recognition technology to the edges of the room introduces new technical and functional requirements – the tech needs to fit into thin form factors while still providing excellent voice recognition performance from across the room. In the case of audio visual equipment, the voice interface needs to support barge-in over multi-channel sound output, which means the microphone array has to process and minimize acoustic echo from stereo audio channels.

The new XMOS VocalFusion Stereo Development Kit for Amazon AVS is designed to meet the heightened requirements for these edge-of-room stereo devices such as smart TVs, set-top boxes, and sound bars. It offers:

• Far-Field performance in challenging audio environments: Voice-recognition performance at far-field distances, and with true stereo Acoustic Echo Cancellation (AEC), making it suitable for devices that operate in noisy environments, are far from the user, and play back stereo audio. 
• Compact form factor: The single-row 4-mic array adds minimal depth to the device, making this reference solution suitable for devices with thin bezels and tight mechanical constraints.
• Optimized for wall-mounted devices: Optimized for use from one-side of the device. The mic array can be mounted facing upward or outward.

The development kit features four microphones spaced 33mm apart in a 100mm linear array. It is built around XMOS’ XVF3500 voice processor, and in addition to two channel full-duplex stereo AEC, it features adaptive beamforming, noise suppression, de-reverberation, and gain adjustment to optimize voice-recognition performance.

“As Alexa expands beyond table-top experiences and into edge-of-room devices, developers are looking for new ways to integrate Alexa seamlessly into the home environment where she can respond from anywhere in the room,” said Priya Abani, Director, Alexa Voice Service at Amazon. “This new stereo far-field linear development kit for AVS from XMOS provides the thin-form factor and high performance needed for these new device types. It opens up fresh opportunities to add Alexa in new ways to stereo home entertainment and wall-mounted AV equipment.”

The new stereo development kit joins the existing XMOS mono VocalFusion 4-Mic Development Kit for Amazon AVS.

Getting Started with AVS

The Alexa service is always getting smarter both for features and for natural language understanding and accuracy. As a developer, your product also gains access to new capabilities with Alexa through API updates, feature launches, and custom skills. Learn how AVS can add rich voice-powered experiences to your connected products on the AVS Developer Portal.

Have questions? We’re here to help. Visit us on the AVS Forum or Alexa GitHub to speak with one of our experts.