From C9 Trader, audio devices can be pre-selected before a call is answered. Right-click the button of the incoming call and select the device you wish to use (Figure 1):
Figure 1 Pre-selected audio device
On an active call, right-click in the call well and select the device you wish to switch to (Figure 2):
Figure 2 Change device during an active call
From the CloudHub, audio devices can be pre-selected before a call is answered. Select the device you wish to use and then press the button you wish to answer/initiate a call from (Figure 3:):
Figure 3 Pre-selected audio device
Once the device selection has been made, it will turn light green.