Skype for Business, Dial Tone over USB Audio Device when using Skype and Teams

Skype for Business, Dial Tone over USB Audio Device when using Skype and Teams

When using a USB audio device with Skype for Business and Teams you may be presented with the traditional dial tone or busy signal through your currently connected USB audio device. This can happen during phone calls or at random. This is a USB audio device limitation due to how various OS such as Windows and Mac handle overlapping device drivers for multiple programs. This problem is not specific to any given device and could impact any USB audio device used with Skype and Teams.

There are number of ways to mitigate this if you are experiencing issues:

  • Switch to the Web version of Teams at:, using your favorite web-browser. Make sure to close the Desktop app completely by Quitting it from the system tray on Windows and the menu bar on Apple.


  • On any computer experiencing this issue you can mitigate this by closing Teams completely so only Skype is open on the computer.


  • Or you can select different audio devices for Teams and Skype:

In the Skype for Business main window, go to Tools > Options > Audio Device, and then choose another device

In the Teams desktop app click on Ellipsis (...) > Settings > Devices and then choose another device

In Skype uncheck the Secondary Ringer option by going to Tools > Options > Audio Device > Uncheck the box under Secondary ringer.

You can also switch to a non-USB device for audio calling.

Note: This has been a known issue, to Microsoft, for groups in an intermediate stage of transitioning from Skype for Business to Teams (aka Islands-Mode), the current plans are to complete the migration to Teams by late May, 2023. This document will be removed after the migration is completed.

Keywords:Skype for Business, USB, SFB, Dial Tone, Busy Signal, Fast Busy, Teams   Doc ID:123699
Owner:Lync M.Group:University of Illinois Technology Services
Created:2023-01-31 15:59 CDTUpdated:2023-03-01 11:15 CDT
Sites:University of Illinois Technology Services
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