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How to stop Windows AI features from changing audio encoding?

Finn Emmerson 0 Reputation points
2025-08-09T04:46:30.16+00:00

I just got a Copilot+ PC, and I noticed that whenever I open an app that uses local AI features, like Click To Do and Recall, the system audio encoding changes to a very noticeably lower quality. The encoding does not change back until the app (and any associated processes) are stopped, and in the case of music, it is paused and resumed. A similar thing happens when you are recording audio for any reason (like on a voice call or a game with voice chat. Why would this be happening when these AI features aren't (visibly) recording audio? How can I make it stop?

To reproduce (requires a Copilot+ PC):

  1. Begin playing relatively high-quality media through relatively high-quality headphones/speakers. I am using Spotify and AirPods.
  2. Open the Recall app, or hold Win+Q to open Click To Do.
  3. The audio quality should've noticeably degraded (a known result of changing to a lower quality audio encoding that supports simultaneous audio input and output)
  4. Close the Recall app (Recall can still be running in the background), or go into Task Manager and quit the Click To Do task.
  5. Pause, wait a second or two, and play your music again
  6. The audio quality should've returned to normal.
Microsoft Copilot | Windows Copilot | Copilot+ PC
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  1. Bryan-V 2,040 Reputation points Microsoft External Staff Moderator
    2025-08-09T19:31:37.0966667+00:00

    Dear Finn Emmerson,

    Thank you for reaching out to the Microsoft Q&A.

    Your detailed observation and correct analogy to voice call audio degradation are spot-on. This is not a bug in the traditional sense, but rather a fundamental limitation of current Bluetooth technology that is being exposed by the new "always-on" nature of some AI features in Copilot+ PCs.

    The core of the issue lies in how Bluetooth handles audio. Your AirPods, like most Bluetooth headphones, operate using different "profiles." The two important ones here are:

    • A2DP (Advanced Audio Distribution Profile): This is the high-fidelity, one-way street. It uses most of the available Bluetooth bandwidth to send high-quality stereo audio from your PC to your headphones. This is the profile used for listening to music, watching videos, and gaming (without chat). It supports codecs like AAC (which your AirPods use), SBC, and aptX, providing a rich listening experience.
    • HFP/HSP (Hands-Free Profile / Headset Profile): This is the lower-fidelity, two-way street. This profile is activated whenever an application needs to use your headphone's microphone. To support simultaneous audio output (hearing) and audio input (speaking), the protocol drastically reduces the quality of the output audio. It switches to a low-complexity, mono codec with a much lower bitrate. This is why music sounds flat, tinny, and "low quality" the moment you join a Zoom call or start a game with voice chat enabled.

    To stop this issue, you could try following these steps:

    1. Manually set your microphone device:
      • Make sure your AirPods are connected.
      • Right-click the speaker icon in your system tray and select Sound settings (or go to Settings > System > Sound).
      • In the Output section, make sure your AirPods are selected. You might see two options, such as "AirPods Stereo" (for A2DP) and "AirPods Hands-Free AG Audio" (for HFP). Ensure Stereo is selected.
      • In the Input section, this is the crucial step. Click the dropdown menu and explicitly select your PC's internal microphone, which is likely named something like Microphone Array (Realtek Audio) or Internal Microphone. Do NOT select the AirPods microphone.
    2. For guaranteed audio fidelity without any compromises, a wired connection is foolproof. Plugging in a pair of wired headphones via the 3.5mm jack or a USB-C connection bypasses all Bluetooth profile limitations entirely.

    To assist others who might have similar questions and to help us improve our support system, we kindly encourage you to "Accept the answer" if it successfully addressed your concern. Accepting an answer lets other users know that this solution worked for you, and it also helps us track the effectiveness of our support efforts.

    Best regards, 

    Bryan Vu | Microsoft Q&A Support Specialist 

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