After upgrading VDA from 2203 LTSR to 2402 LTSR, mic volume set to 0 in ICA/HDX session connected from Citrix Worksapce app 2203.1 LTSR.

1. Upgrade Citrix Workspace app for Windows from 2203.1 LTSR to 2305.1 or later version.
2. Delete the regisry key HKEY_CURRENT_USER\SOFTWARE\Citrix\aspmon.

Problem Cause

VDA 2305 or earlier versions, including 2203 LTSR, use SetMasterVolumeLevel/GetMasterVolumeLevel, which operate in decibels. In these versions, both the maximum and default volume level values are 0, and the volume level is saved under HKEY_CURRENT_USER\Software\Citrix\aspmon.

In contrast, VDA 2308 or later versions utilize SetMasterVolumeLevelScalar/GetMasterVolumeLevelScalar, which employ a normalized, audio-tapered value ranging from 0.0 to 1.0 for the volume level.

When connecting from Citrix Workspace app 2305 for Windows or later, the audio volume level is synchronized between the VDA and the Citrix Workspace app. However, if connecting from Citrix Workspace app 2303 or earlier, the audio volume level is retrieved from HKEY_CURRENT_USER\Software\Citrix\aspmon.

In VDA 2305 or earlier, a volume level value of 0 represents the maximum volume, whereas in VDA 2308 or later, it signifies the minimum volume.