Please describe the problem:
When selecting sound devices for output (ring device, output device) there is no way to test whether the selected device actually works. Such a function ("Play a test sound") are common in other sip phones e. g. Skype or Wengophone. The lack of testing creates a hard situation when configuring, since the "no sound" error could be either a problem with the device, the attached hw or with the network.

Steps to reproduce:
1. Select Edit | Preferences  | Audio | Devices
2. Change the Output device
3. Change the Ringing Device


Actual results:
The sound possibly works, or not; I have no way to know.

Expected results:
Buttons labeled "Play test sound" for the Output Device and the Ringing Device, with the obvious function.

Does this happen every time?
Yep.

Other information: