Lately I noticed this telezapper popping up in retail stores (radio shack, Kmart etc) for around $50. I was curious as to how it actually worked so I dug around the web for it. What I found out is that these types of devices just emit a SIT (Special Information Tone) tone that tells the telemarketers that your phone is actually disconnected. Here's a good website that i found information on. He sells his own telezapper but you can just download the SIT tone and record it to your answer machine!
<< Put it in front of one or all your phones (and your answering machine), and it will play a SIT (Special Information Tone) whenever you or your answering machine answers your line. The SIT tone is the short "doo-doo-doo" sound you hear when you dial a disconnected number - before the recording says the line is disconnected. >>
<< Telemarketers and Bill Collectors often use Predictive Dialers to dial outgoing calls. These are computers that keep dialing phone numbers on a list until they reach a live person. The Predictive Dialer then transfers that call to the first live operator. That's why you hear silence for a while before someone gets on the line, when you answer the phone sometimes. Some of them are bold enough to play a little recording asking you to "Please hold on for an important call!" Right. >>
<< Telemarketers and Bill Collectors don't want to pay their operators to dial the phone and listen to busy signals and answering machines, so they have a computer do it for them. The Predictive Dialer is programmed to hang up if it hears a SIT tone, since it knows the line is disconnected. It doesn't listen to what's said after the SIT tone, since it doesn't understand words. The Telemarketer or Bill Collector often takes that number out of their database too, so it won't be called again! >>
<< Put it in front of one or all your phones (and your answering machine), and it will play a SIT (Special Information Tone) whenever you or your answering machine answers your line. The SIT tone is the short "doo-doo-doo" sound you hear when you dial a disconnected number - before the recording says the line is disconnected. >>
<< Telemarketers and Bill Collectors often use Predictive Dialers to dial outgoing calls. These are computers that keep dialing phone numbers on a list until they reach a live person. The Predictive Dialer then transfers that call to the first live operator. That's why you hear silence for a while before someone gets on the line, when you answer the phone sometimes. Some of them are bold enough to play a little recording asking you to "Please hold on for an important call!" Right. >>
<< Telemarketers and Bill Collectors don't want to pay their operators to dial the phone and listen to busy signals and answering machines, so they have a computer do it for them. The Predictive Dialer is programmed to hang up if it hears a SIT tone, since it knows the line is disconnected. It doesn't listen to what's said after the SIT tone, since it doesn't understand words. The Telemarketer or Bill Collector often takes that number out of their database too, so it won't be called again! >>