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If you are using Asterisk or another software PBX to connect to Google Voice, and you or some of your users are using VoIP adapters, you may be familiar with a phenomenon called “talkoff”, where the human voice somehow creates a sound that the adapter confuses with a touch tone digit, so it actually sends a touch tone digit. This was more of an annoyance than anything until recently, when Google Voice found a way to use it to make people think their calls were being bugged! Well, I’m sure that was not the intent, but it sure was the effect!
See, Google Voice turned on this new feature, that you might have noticed in a message in your Google Voice portal (if you ever log into the Google Voice web site, that is):
Yes, you can now record calls at any time by pressing “4″ on your phone’s dialpad – but take a wild guess which touch-tone digit is commonly created when “talkoff” occurs?
So, out of the blue, both the caller and the called party hear an announcement that their call is being recorded. They have no idea where it came from, or who’s doing the recording (the recording doesn’t mention Google Voice). This typically results in a very strong desire to immediately terminate the call by both parties!
So how do you disable it?
Google Voice settings page - uncheck "Call Options"
Go to the Google Voice “Settings” page, click on the “Calls” tab, uncheck the box next to “Call Options” (while you are there you may want to enable Global Spam Filtering, if it’s not already checked, but that’s entirely up to you), and then click the “Save Changes” button. That will turn off the “press 4 to enable recording” feature (and may just save your marriage or your current relationship)! 
Paul Timmins said
THEY FINALLY MADE A SETTING TO TURN THAT OFF? NOW I CAN NAVIGATE TOUCH TONE MENUS WITH A 4 IN THEM! YAY!!!!!
The talkoff is more common with a linksys ATA. The way to get around it is to use inband DTMF with the ATA.
Ward Mundy (@NerdUno) said
Great tip! Thanks.