Today I moderated a webinar where the primary presenter was working from home. We were logged in well ahead of time, verified the slides, went through the usual pre-flight checklist, and ran a sound check. Everything was in good shape. Right before I pushed the button to take us live to the audience, I asked her: "Ready to go?"
"Y-mmphrbl-bzz"
"Uh oh. Wait a minute. Talk to me again."
"Why? What's the m-zzr-brbl?"
"What kind of phone are you on?"
"My cordless phone at home."
Ugh. An old enemy, back to torment me. We tried going live anyway, and for a minute or two she sounded fine. And then the warbling, garbling, and interference started again. Eventually she disappeared altogether. I wrote her a note in the webinar chat and told her she had to find another phone. She did, while I kept the audience entertained with some tap dancing and a poetry recitation.
Let's see… What's the most subtle way I can put this? NEVER USE A CORDLESS HANDSET ON A WEBINAR!!!!
I'm not talking about cellular phones or smart phones. I'm talking about home phones that sit and recharge in a tabletop cradle. The cradle is connected to the telephone wall jack and the handset can be lifted out of the cradle and carried around for convenience.
These things are evil. EVIL I TELL YOU! Older units communicate between handset and base unit using an unlicensed (in the USA) wireless frequency shared by all kinds of other consumer goods, from baby monitors to pacemakers to microwave ovens. You can get interference at any time from a signal suddenly slopping over into your reception range. There is no way to predict it, track it, or solve it.
Newer cordless phones have adopted a different operating frequency, specified by the acronym DECT. The United States uses a different version of DECT than almost every other country in the world, because of course we do. Reading from the infinite wisdom of Wikipedia, I find this delightful nugget of information:
In North America, DECT suffers from major deficits, especially in comparison to DECT elsewhere, since the UPCS band (1920–1930 MHz) used for DECT in North America is not free from heavy interference and only half as wide as that used in Europe (1880–1900 MHz), the 4 mW average transmission power limits the range to far less than the 10 mW permitted in Europe, and the commonplace lack of GAP compatibility among US vendors binds companies to a single vendor.
Interestingly, I was once told by a phone company tech rep that cordless base stations can mess up the call quality and clarity across other hardwired phones in your house, even if the cordless phone is not in use!
Please, if you are presenting from your home… Unplug any cordless phones from their phone jacks and present from a good old fashioned desk phone. Your moderator and your attendees will thank you.