Over the weekend, Microsoft released new Windows Insider previews. These bring a preview of “Shared Audio” for Bluetooth LE. This allows two Bluetooth devices to play Windows sound simultaneously.

Microsoft has been working on improving Bluetooth support in Windows for some time. Over the course of the year, Windows is expected to support new facets of the Bluetooth Low Energy (LE) wireless standard. This now apparently includes a part of Bluetooth “Auracast,” which Microsoft is building upon for “Shared Audio,” according to the Windows Insider Blog. According to the specification, Auracast can send sound to an unlimited number of receivers with an audio sender. “With Shared Audio, your supported Windows 11 PC can broadcast an audio stream to two Bluetooth audio accessory devices simultaneously,” Microsoft explains there; it “enables sharing your audio over two separate headphones, speakers, earbuds, or hearing aids.”

Use Cases

Microsoft also suggests use cases for the new feature: Students could listen to music together while studying. Or “shared audio” can bring family members closer together who are watching a movie together on a trip.

Windows 11, in its preview version on compatible hardware, features a new quick setting for Shared Audio.

(Image: Microsoft)

However, there are hurdles to overcome to use it. To enjoy shared audio, Bluetooth LE audio-compatible accessories must be paired and connected to the Windows 11 PC. Interested users will need to use the new “Shared Audio (Preview)” tile in the quick settings. Clicking “Share” starts sharing, and “Stop Sharing” ends it.

However, there isn’t much compatible hardware available yet. Microsoft lists Surface laptops with 13.8 and 15 inches with Qualcomm Snapdragon X and the Surface Pro with 13 inches and Snapdragon X, as well as their business versions, among currently usable devices. Microsoft also plans to support Samsung Galaxy Book5 360, Pro, and Pro 360 laptops with Intel Core Ultra 200 processors, Samsung Galaxy Book4 Edge with Snapdragon X, and Surface Laptops with 12 and 13 inches with Snapdragon X, along with their business counterparts, soon. As output devices, Microsoft currently lists Samsung Galaxy Buds2 Pro, Buds3 and Buds3 Pro, Sony WH-1000XM6, and recent LE audio-enabled hearing aids from ReSound and Beltone. However, this is not an exhaustive list, and other devices may also be supported, Microsoft explains.

The latest Windows Insider version in the Developer or Beta channel must be installed on the supported Copilot+ PCs. The feature might take a while to become available, as Microsoft is rolling it out gradually.

At the end of August, Microsoft integrated an improved version for Bluetooth’s so-called Hands-Free Profile (HFP). If the microphone of Bluetooth headsets is used, the connection switches to this profile. Unlike the Advanced Audio Distribution Profile (A2DP), HFP could previously only output mono sound up to 8-16 kHz, which was also heavily compressed – reminiscent of the muffled sound of old medium-wave radio. At least “Wideband Voice” was added to HFP, doubling the sample rate to up to 32 kHz.

However, Bluetooth LE Audio now allows more; there is a “Telephony and Media Profile” (TMAP) for both media playback and telephony. Microsoft explains in a blog post that LE Audio comes with improved compression and TMAP requires Bluetooth hardware to support a 32 kHz sample rate in voice profiles. About two months ago, Microsoft added “Super Wideband Stereo” for LE Audio Voice. This allows high-quality stereo sound even when using the microphone, for example, in games or phone calls. However, developers of Bluetooth hardware and communication software need to make adjustments. These improvements are made possible, among other things, by the significantly better capabilities of the LC3 codec (Low Complexity Communications Codec), which is integrated into Bluetooth LE Audio and supports sample rates of 8, 16, 24, 32, 44.1, and 48 kHz, data rates from 16 to 320 kBit/s, and frame sizes of 7.5 and 10 milliseconds – and the separate transmission of individual audio channels, for example, for stereo sound. (dmk)

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This article was originally published in German. It was translated with technical assistance and editorially reviewed before publication.