While in an ICA session if you left-click on the speaker icon in the system tray nothing happens. This should bring up a volume bar, as it does on the machine in console Right-click brings up the context menu and you can change the volume through the mixer.
To resolve this issue, change permissions for the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\citrix\Audio
Issue resolved in CU1 update LC7000.
Citrix Documentation - Fixed issues .
The Windows Shell Experience Host might exit unexpectedly when you click the volume control on the taskbar. [#LC7000]