[Asterisk-Users] Horrible BUZZZZ noise when sounds/music play on SIP phone?

[Peter Svensson]

On Wed, 24 Nov 2004, Andrei (MPI) wrote:

> David Boyd wrote:
> >On Wed, 2004-11-24 at 04:14, Mike Dent wrote:
> >>Hi,
> >>I've recently set Asterisk up, 1.0.2 version. With 1 x X100P card and
> >>1 SIP phone.
> >>I've noticed some horrible buzz/rasping type of sounds! These seem to occur when
> >>* is trying to play back some audio or sound to me?
> >>
> >>E.g. If I have an exten rule which plays one of the music on hold
> >>files when I dial 800 lets say,
> >>I get a really loud buzz for about 2 seconds and then the music plays.
> >>
> >>E.g. 2. If I dial 500 to connect to Digium, as the call is connecting
> >>I get the same loud
> >>buzz noise for 0.5 seconds or so.
> >>
> >>Not sure where this is coming from? I did a search on the wiki for
> >>buzz/hum/rasp but could
> >>not find anything.
> >
> >Sound like an IRQ issue. Check to see if you are sharing an interrupt on
> >your X100P card, take a peek with " cat /proc/interrupts (on linux at
> >least) :)  
> 
> ..and stop running X (x-windows) on your Asterisk box. :)

It could be the echo canceler. If the line is completely quiet the echo 
canceler seems to diverge. I think there was a bug in the bug tracker 
about this that got fixed a while back.

http://bugs.digium.com/bug_view_advanced_page.php?bug_id=0002820

The fix was merged on 2004-11-17. It may be a good idea to update and 
check again.

Peter