Comment 4 for bug 540181

Sound is better for people who hate blinking...it's a matter of taste ;-)

Anyway, the sound notifications I propose should only be played if the chat window was not active, minimized or closed. Also, the user should be able to extend the interval the notifications are played. So, you can have a situation like this:

**10.00.00: chat window inactive, minimized or closed
10.00.01: incoming message from contact1 -> sound
10.00.05: incoming message from contact2 -> NO sound
10.00.09: incoming message from contact3 -> NO sound
10.00.15: incoming message from contact1 -> NO sound
10.01.25: incoming message from contact2 -> NO sound
10.01.45: incoming message from contact4 -> NO sound
10.02.01: sound as a reminder 2 minutes after the first unread message
10.02.05: incoming message from contact1 -> NO sound
10.03.07: incoming message from contact2 -> NO sound
**10.03.10: chat window activated
10.03.27: incoming message from contact3 -> NO sound
**10.03.47: presence status changes to away
10.04.01: NO sound
10.04.55: incoming message from contact1 -> NO sound
10.05.07: incoming message from contact2 -> NO sound

Some advantages:
* If you don't want to be bothered by sounds when you leave your computer, you can simply keep the chat window opened.
* Sounds become a reminder instead of an annoying jingling.
* The user can define the reminder interval. If she sets it to "zero", sounds will be disabled. If she sets it to "infinite", sounds will only once be played when the first message is received.