Surface Laptop for Business 7th Edition – all microphones disappear after Intel Smart Sound Technology OED / DSP crash

have a Surface Laptop for Business 7th Edition with Intel running Windows 11.

Intermittently, the entire microphone/input audio subsystem disappears.

Typical symptoms:

• Bluetooth headphones remain connected.

Audio playback may initially stop and later recover.

After playback recovers, microphone input does not recover.

Windows shows no available microphone.

Microsoft Teams shows no microphone under Devices.

Other applications also cannot detect any microphone.

The microphone/audio icon in the taskbar shows an error/cross.

Disconnecting/reconnecting the Bluetooth headset does not fix the problem.

The only reliable recovery is restarting Windows.

This is not specific to one Bluetooth headset. I have reproduced similar behavior with different Bluetooth audio devices.

Diagnostics captured immediately after the failure show:

Intel Smart Sound Technology OED: CM_PROB_DRIVER_FAILED_PRIOR_UNLOAD

Intel-SST-OED Event ID 22: Set DSP state. Firmware crashed (timeout) - resetting., STATUS = STATUS_TIMEOUT.

Immediately afterwards Kernel-PnP Event ID 219 is logged repeatedly:

The driver \Driver\IntcOED failed to load.

Device: INTELAUDIO\DSP_CTLR_DEV_A828&VEN_8086&DEV_0222...

Status: 0xC000038E

At the same time Windows Audio and Windows Audio Endpoint Builder services are still running, but audio input endpoints disappear.

The issue has occurred repeatedly. For example:

25 Sep 2026 around 16:08

26 Sep 2026 around 16:53

The laptop is fully updated through Windows Update and Surface updates.

Please investigate the Intel Smart Sound Technology OED / DSP firmware or driver recovery path. The driver apparently crashes and does not successfully reload, leaving Windows without microphone endpoints until reboot.have a Surface Laptop for Business 7th Edition with Intel running Windows 11.

Intermittently, the entire microphone/input audio subsystem disappears.

Typical symptoms:

Bluetooth headphones remain connected.

Audio playback may initially stop and later recover.

After playback recovers, microphone input does not recover.

Windows shows no available microphone.

Microsoft Teams shows no microphone under Devices.

Other applications also cannot detect any microphone.

The microphone/audio icon in the taskbar shows an error/cross.

Disconnecting/reconnecting the Bluetooth headset does not fix the problem.

The only reliable recovery is restarting Windows.

This is not specific to one Bluetooth headset. I have reproduced similar behavior with different Bluetooth audio devices.

Diagnostics captured immediately after the failure show:

Intel Smart Sound Technology OED:
CM_PROB_DRIVER_FAILED_PRIOR_UNLOAD

Intel-SST-OED Event ID 22:
Set DSP state. Firmware crashed (timeout) - resetting., STATUS = STATUS_TIMEOUT.

Immediately afterwards Kernel-PnP Event ID 219 is logged repeatedly:

The driver \Driver\IntcOED failed to load.

Device:
INTELAUDIO\DSP_CTLR_DEV_A828&VEN_8086&DEV_0222...

Status:
0xC000038E

At the same time Windows Audio and Windows Audio Endpoint Builder services are still running, but audio input endpoints disappear.

The issue has occurred repeatedly. For example:

25 Sep 2026 around 16:08

26 Sep 2026 around 16:53

The laptop is fully updated through Windows Update and Surface updates.

Please investigate the Intel Smart Sound Technology OED / DSP firmware or driver recovery path. The driver apparently crashes and does not successfully reload, leaving Windows without microphone endpoints until reboot.Audio-Diagnostics-20260926_165713.txt

P.S. Making users manually navigate this tag maze for a Windows power-management bug is impressively unfriendly.