In a small, intimate conference call, you might not mind an alert when colleagues join your line so you know when it's time to begin. However, when meetings exceed 5-6 participants, all coming from their previous meeting at different times, you might want to disable this setting so that the speaker is not interrupted by latecomers.
You can configure this setting using the WebEx plug-in to Outlook. Just select the No Tone option on the drop-down for meetings.
As a best practice, I use this if my meeting exceeds half a dozen participants.
Unfortunately, this method is not foolproof. If you are in a meeting with the announcements option enabled and you need to shut it off in real time, try pressing *2. Note that you can likely only do this when you are dialed in as the leader of the call. *6 can mute all of your conference participants' phones. You can find a full list of commands on Cisco's page.
I hope that these tips will help your conference calls to run a little more smoothly!
Keep in mind that sometimes, things to not go as planned, and you need to call in the big guns. This happened in a conference call today, in which I was presenting a talk to a large (70+) audience about work/life balance. Luckily, my colleague and I had the foresight to dial in 30 minutes prior to the start of the meeting. This is always an excellent idea in a big meeting!
We noticed that despite adjusting the No Tone setting, we were still getting the "Now Joining" alert for a new participant. At this point, we called Cisco's WebEx customer service line at (866) 229-3239. We were able to change the setting for the conference going forward, but not the meeting we were in. So to avoid sending a revised meeting to everyone, we called the operator at *0, who was able to change this setting. Remember this option for your next big conference call!