Buzzing through speakers when meeting starts

[Lebers]

Just recently when I start a zoom meeting a constant buzzing goes to the speakers. As soon as the meeting stops the buzzing stops. No other program on the pc does this. I am using windows 11 and zoom 6.4.6. The audio does not get heard by the participants on zoom but it is heard live. Right now the sound is sent from the pc into a mixer and out to speakers throughout the building. Even when the computer sound is all the way off there is still a buzzing. We have tried sound setting in zoom, new cables, a new sound card and updating drivers. Again the sound is just fine until the zoom meeting starts when the buzzing starts and ends when the zoom meeting ends, Not when zoom opens only when the meeting starts.

[jrmagno]

The fact that:

• The buzzing only happens when a Zoom meeting starts (not just when the app is open)

• The buzzing is not heard by participants

• You've already tried new cables, a sound card, driver updates, Zoom audio settings

• And it happens even when the PC volume is at zero

…strongly suggests this is electrical interference or grounding-related, triggered by Zoom activating certain audio hardware functions during a live meeting (like audio processing, mic activation, or echo cancellation).

When a Zoom meeting starts, it activates:

• Live mic input & speaker output

• Audio processing subsystems (echo cancellation, AGC, noise suppression)

• Possibly WASAPI or ASIO audio drivers, depending on your sound setup

These can introduce high-frequency electrical noise — and if your signal path to the mixer isn't properly isolated, it can result in a ground loop hum or buzzing that's not carried digitally (so Zoom participants never hear it), but does feed into analog output lines and speakers.

Try disabling Zoom’s audio processing features

• Go to Zoom Settings → Audio

• Click "Advanced"

• Try toggling or disabling:

  • "Enable audio enhancements"

  • Echo cancellation

Check power isolation

Try:

• Running the PC and mixer from the same power strip (to ensure same ground)

• Or, better yet, use a power conditioner (like Furman) for your audio rack

Test with another PC

If a laptop (on battery only) doesn't cause the buzz, that confirms the issue is with your PC’s grounding or audio subsystem and not Zoom itself.