As telemarketers have figured out my cell phone number and I’m getting automated calls, I was wondering if this plan would work. At the start of my answering machine message, play the three-tone sound that signifies a disconnected phone line. Would that trigger a note with the automated dialer that the line no longer works and to stop calling that number, or since it’s computerized and can dial so many numbers it won’t care?
I don’t know the answer but I say go for it and let us know if it works. If it does, it’s fucking BRILLIANT!
Gadgets to do this were all the rage in the 1990s. I remember one was called the Telezapper. You plugged your phone into it and it would also play a SIT tone everytime you (or your answering machine) answered the phone.
But there is a problem: They may also disconnect legitimate calls using automated calling equipment, for example, a call from your doctor’s office about an appointment or a call from your child’s school about an emergency closing or a lockdown or some panic.
I read rumors that many calling systems were modified to get around this, but I can’t confirm that.
Here: you can still buy a Telezapper. Obviously, it won’t work for cell phones.
I bet they in fact don’t want to purge disconnected numbers from their system, because eventually disconnected lines get reconnected.
Our home internet is by DSL over a wired phone to a desktop PC to a router. I installed an older version of “Phone Tray” (free download) on the PC which has this and other “zapping” options. Works great.
I like PhoneTray so much I bought their PhoneTray Pro with all the bells and whistles. It is so satisfying to hear my machine hang up on their machine.
I thought that Nomorobo also worked on some wireless carriers, but apparently not.
Shame. We signed up a couple months ago for our VoIP line and it’s made a dramatic difference.
With cell phones, we block* individual numbers and over time it gets better.
- Okay, our carrier doesn’t do “blocking”. I add the number to a group where the phone doesn’t ring.
Second PhoneTray Pro. Works great for landlines and has a bunch of pre-installed Zap messages you can select, including the classic “Disconnected” message.
I’d like to have an accessory that imitates the annoying sound you hear when you dial a fax machine by mistake! 
Just keep an air horn near your phone.
I have the disconnected line tone on my answering machine. Rough guess, it may have reduced calls by 25% or so, but most calls are recordings and they don’t seem affected by it.
An air horn would be good for that. Who knows, it might blow some circuits. Serves them right.
I third the use of PhoneTray Pro. I’ve been using it for several years (found out about it here on the Dope) and it does seem to have cut down these calls a lot. However, it isn’t an app for cellphones, only landlines. Plus it won’t work 100%, a lot of persistent agencies are aware of the ‘three-tone’ trick and have their systems ignore it (i.e. they still keep calling).
BTW it doesn’t matter what kind of landline phone service you have (cable modem, DSL, POTS etc.), all you need is a little USB modem (eBay has them for $10) and a Windows PC and it will work (you have to leave your PC turned on 24/7).
For unwanted cell calls I simply put them into My Contacts as ‘DO NOT WANT’ (:D) and assign a silent, non-vibrating ringtone to them.
If it’s a smart phone, there are tons of apps for blocking unwanted calls - I use Whitepages Caller ID - it knows lots of spam callers already and will let you block new numbers easily.
I had a Telezapper years ago. It seemed to help but not much. The idea was that the telemarketers would tell each other that your line was disconnected. I doubt that they share all that much or that often. I bought a Call Blocker for my land line and it does a much better job.
For my Android cell phone, I use the Call Control app. It works well.
I should’ve pointed out that I only had to do this because originally, before iOS 7 or 8 I think, the at&t iPhones didn’t let you do on-device call number blocking. It was a carrier-plan option only (so that you had to pay a couple bucks extra for it*!*) Was one of the biggest sources of at&t iPhone user complaints back then. Now you can just block any number right on the iPhone itself.
With my cell, whenever I get a call from a number I don’t recognize (or has its name/number blocked) I send it straight to voicemail. And if they don’t leave a message I immediately block it. With my landline and PhoneTray I also used to let numbers go thru and then add them to a black list as needed. But I was getting so many unsolicited calls I switched it to allowing white list numbers only (i.e. just My Contacts).
I’m with Verizon. As I recall you have to pay to block numbers with them. 
Google Voice does this too. If you add a number to your blocklist, the next time that number calls they’ll hear a fake “duh duh duh… the number you have called is not in service…” message.
There are still telemarketing calls in 2016:eek:
Good god yes! Now more than ever, not the least of which because phone rates are practically zero now (no long distance fees at all). And because of the ubiquity of cell phones. We’ve gone from every home having a phone number to every single individual person having one (most all of which get emails and texts too!)