Cheers for the replies. I'm not sure if I'm replying properly but here goes. I'm using Polycom 650 phones. I'm not really sure what a 60hz ground loop is so will need clarification, sorry I'm new to this. The phones are all on the same LAN and the conferencing is done on internal calls. Cheers From: stormin.normin@hotmail.co.uk To: freeswitch-users@lists.freeswitch.org Date: Wed, 1 Apr 2009 22:09:03 +0100 Subject: [Freeswitch-users] Buzzing when people speak in conference Hi, I've been asked to do some testing on Freeswitch by work, we currently use Asterisk. I'm quite new to telephony so please go easy. I have FS setup on a windows box and at the moment I'm testing internal calls only, when I transfer calls or call extensions everything sounds great. The problem occurrs when I setup conferencing, people can log in ok and we can talk, the trouble is as people start to talk a buzzing sound is heard in the background, once the talking stops the buzzing stops. If the person goes on mute there is no buzzing. Hopefully this is enough info cheers for any help. " Upgrade to Internet Explorer 8 Optimised for MSN. " Download Now _________________________________________________________________ View your Twitter and Flickr updates from one place – Learn more! http://clk.atdmt.com/UKM/go/137984870/direct/01/