# Is (or was) there anything inherently numeric about phone numbers? **URL:** \ **Category:** Factual Questions\ **Created:** [January 24, 2020, 5:18pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905 "2020-01-24T17:18:15Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [January 25, 2020, 4:30pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/41 "2020-01-25T16:30:30Z")
> [@engineer\_comp\_geek](#): > > The last one I personally knew of was in the 1980s. I did a bit of googling to see if any still existed. I figured there had to be at least a few oddballs out there. > > According to AT&T, there are still thousands of “party lines” out there, but most only go to a single user these days (hence the quotes). All of the other users have dropped off of the service, but there is at least one customer still using the original party line. > > I also found a reference to a camp with a bunch of cabins in California that still uses a party line. I think my folks had a party line into 1977 or so. They were happy to be rid of it. ---
**Author:** ![squidfood](https://avatars.discourse-cdn.com/v4/letter/s/a87d85/32.png) [@squidfood](https://boards.straightdope.com/u/squidfood)\ **Post date:** [January 28, 2020, 1:05am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/42 "2020-01-28T01:05:58Z")
> [@](#): > > In this paper, we being the study of a class of mathematical expressions of the form x1 x2 x3 - y0 y1 y2 y3, x,y E [0,1,2…9]. Such expressions are generally known as the phone numbers. They involve the subtraction of a four digit number from a three digit number. These numbers are compiled annually and published by the local phone companies that were at one time associated with Bell Labs. Opening paragraph to “The Mathematics of Telephone Numbers”, from the Annals of Improbable Research 1:5 (Sept/Oct 1995). ---
**Author:** ![mtnmatt](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@mtnmatt](https://boards.straightdope.com/u/mtnmatt)\ **Post date:** [January 29, 2020, 12:42am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/43 "2020-01-29T00:42:30Z")
My friends had a party line at their house in the Cape Cod National Seashore until about 1980. When I was young, in my grandparents’ tiny village in upstate NY, all you needed to dial for a local call was the last 4 digits I was once working on developing an audio-text system that used touch tones as the commands. We’d upload audio recordings from focus groups about various market-research topics (eg, press 1 to hear about cheese, press 2 to hear about crust on a project for Pizza Hut). I was really frustrated when one clip could not get uploaded completely - it would always cut off. It turned out that one of the respondents’ voice exactly mimicked the tone combination for whichever was the command for “stop recording” so we had to get a special filter to eliminate just the frequencies that corresponded to the key tones (which are actually combinations of the tones in the 3 columns and 4 rows, as I came to understand it). ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [January 29, 2020, 1:28am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/44 "2020-01-29T01:28:11Z")
> [@mtnmatt](#): > > I was once working on developing an audio-text system that used touch tones as the commands. We’d upload audio recordings from focus groups about various market-research topics (eg, press 1 to hear about cheese, press 2 to hear about crust on a project for Pizza Hut). I was really frustrated when one clip could not get uploaded completely - it would always cut off. It turned out that one of the respondents’ voice exactly mimicked the tone combination for whichever was the command for “stop recording” so we had to get a special filter to eliminate just the frequencies that corresponded to the key tones (which are actually combinations of the tones in the 3 columns and 4 rows, as I came to understand it). There are 4 columns, not 3, in the specification, giving a total of 16 buttons. Only 12 buttons are used in the civilian version of Touch-tone. The other 4 signals were intended for other uses, for example, signaling security & encryption levels on military phone systems. I don’t know how much they wer actually used for that in practice. Possibly the extra 4 are used now for internal phone system signaling? Or are they just abandoned as an archaic, unused feature? ---
**Author:** ![MarvinKitFox](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@MarvinKitFox](https://boards.straightdope.com/u/MarvinKitFox)\ **Post date:** [January 29, 2020, 4:35am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/45 "2020-01-29T04:35:32Z")
> [@Fotheringay-Phipps](#): > > (I was contemplating the notion of a system of phone numbers where letters of the alphabet were used instead of numbers. It would be easier to remember the – shorter – phone “numbers”, but would make for a less functional keyboard.) Do you **really** think it would be easier to remember “QpTXd” than “555-1047”? ---
**Author:** ![MarvinKitFox](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@MarvinKitFox](https://boards.straightdope.com/u/MarvinKitFox)\ **Post date:** [January 29, 2020, 4:42am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/46 "2020-01-29T04:42:16Z")
a 5-character alpha word could replace an 7 or 8 digit numeric. but… In addition to the difficulty of memorizing random string of characters(goodness we suffer enough with computer passwords already!), you would need to eliminate a vast amount of potential “numbers” to avoid offense. Or would you want your number to be “whore”,“chink”,“farts”, or any other of many million possibly negative word-lookalikes? ---
**Author:** ![Mr\_Downtown](https://avatars.discourse-cdn.com/v4/letter/m/8e8cbc/32.png) [@Mr\_Downtown](https://boards.straightdope.com/u/Mr_Downtown)\ **Post date:** [January 29, 2020, 4:57am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/47 "2020-01-29T04:57:28Z")
> [@Tim\_T-Bonham.net](#): > > There are 4 columns, not 3, in the specification, giving a total of 16 buttons. Only 12 buttons are used in the civilian version of Touch-tone. Imagine my surprise to see that the wall phone _Young Sheldon’s_ Meemaw was using in a recent episode had a 16-key Touch-Tone pad. I didn’t know anyone ever made a 16-key 2554 set—at least, not one in yellow! ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [January 29, 2020, 6:11am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/48 "2020-01-29T06:11:02Z")
I have encountered 16-key DTMF keypads featuring “A”, “B”, “C”, and “D” keys, but definitely not on a wall phone. Now I wonder what would have happened had I dialed various numbers incorporating those tones… ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [January 29, 2020, 6:26am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/49 "2020-01-29T06:26:23Z")
> [@Mr\_Downtown](#): > > Imagine my surprise to see that the wall phone _Young Sheldon’s_ Meemaw was using in a recent episode had a 16-key Touch-Tone pad. I didn’t know anyone ever made a 16-key 2554 set—at least, not one in yellow! Did you get a close-up enough view to see how those extra keys were marked? My phone has four rows and four column. The fourth column has two special-purpose buttons (redial and mute) and the other two positions have little slide switches. One switch turns the ringer on or off. The other selects tone dial or (simulated) pulse dial. My phone is beige. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [January 29, 2020, 6:28am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/50 "2020-01-29T06:28:24Z")
> [@DPRK](#): > > I have encountered 16-key DTMF keypads featuring “A”, “B”, “C”, and “D” keys, but definitely not on a wall phone. Now I wonder what would have happened had I dialed various numbers incorporating those tones… There would soon come an ominous knocking on your door . . . 😉 ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 29, 2020, 4:53pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/51 "2020-01-29T16:53:36Z")
> [@Tim\_T-Bonham.net](#): > > There are 4 columns, not 3, in the specification, giving a total of 16 buttons. Only 12 buttons are used in the civilian version of Touch-tone. The other 4 signals were intended for other uses, for example, signaling security & encryption levels on military phone systems. I don’t know how much they wer actually used for that in practice. Possibly the extra 4 are used now for internal phone system signaling? Or are they just abandoned as an archaic, unused feature? In my experience (the DoD Automatic Voice Network-- AUTOVON, the US military’s Cold-War-Era long-distance telephone network), those four buttons were for precedence. Punch the “I” button as a prefix to dialing the 7-digit world wide number, and you would establish that your call was “Immediate” precedence and therefore could get long-line resources at the expense of callers at “Routine” precedence (no precedence dialed) or “Priority” (“P” precedence dialed). “FO” was interesting. It means “Flash Override” and could preempt calls in progress in order to get through. (It also meant the other more common expansion of “FO”, because that’s what you’re saying to the folks who get dumped.) FO was supposed to be for stuff like “enemy launch in progress” at the strategic level. Wikipedia photo of an AUTOVON dial pad: [Autovon - Wikipedia](https://en.wikipedia.org/wiki/Autovon#/media/File:66a3aDTMFpad.jpg) ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [January 29, 2020, 5:13pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/52 "2020-01-29T17:13:52Z")
> [@mtnmatt](#): > > When I was young, in my grandparents’ tiny village in upstate NY, all you needed to dial for a local call was the last 4 digits That was true where my parents lived, into the 1980s (unfortunately, it also meant that any call that couldn’t be done with 4 digits was a long distance call). ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [January 29, 2020, 5:55pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/53 "2020-01-29T17:55:32Z")
> [@beowulff](#): > > Interesting, because our consultant was in the London area, and his phone didn’t have letters on it. I wonder if it got phased out by the 90’s. We had one of the old GPO rented telephones throughout my childhood (in fact I’ve still got it in the loft) and it had the letters on it, but they were just a historical curiosity by the time I was old enough to use the phone in the 1980s. It looked just like [this example - same colour and everything](https://secure24.prositehosting.co.uk/revalveit/706/706_green/706_green_02.jpg). Most of my friends had push-button phones by the 1990s but we still had the old rotary phone. Numbers in my town started with 87 so dialling was a rather tedious process (on a rotary phone it takes longer to dial higher numbers, and 0, than low ones). ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [January 29, 2020, 6:25pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/54 "2020-01-29T18:25:55Z")
> [@septimus](#): > > Party lines. Two or more homes shared the same line; different ring-tones informed us who was being called. If you picked up the line to dial out and heard voices you hung up real quick. We had a party line circa 1960; when did they finally go away? We still had a party line on the farm in the 1970’s in Saskatchewan. Our ring was two longs and a short. You could listen in to any conversation on the line, which was shared by probably 10 different farms. To activate the microphone you had to push a little white toggle button. So if you didn’t push that button you could listen in without anyone hearing you. I assume a lot of that went on - the first social media. When you hung ip, a physical linkage pushed the toggle button back out when the hook went down. Aside from the toggle button, the phone looked like any other wall-mounted rotary phone. As for phones that has a TDMF/pulse button… When we moved to the city, touch-tone was available, but it cost something like $3/mo if I recall. That was quite a bit. So lots of people bought phones that had the convenient touch pad, but generated the clicks needed for the cheaper exchange. When the touch tone exchange finally became free, we just flipped the switch on the phone and we were good to go. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [January 29, 2020, 9:22pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/55 "2020-01-29T21:22:16Z")
> [@md2000](#): > > Then over the 90’s and 00’s, most phone companies stopped allowing pulse dialing. Also, most do not support the power required 48V mechanical bells any more. Really? I still have a dial phone that works just fine on my Verizon Fios system, although maybe the network interface box converts the pulses to tones to send out on the line. ---
**Author:** ![Mr\_Downtown](https://avatars.discourse-cdn.com/v4/letter/m/8e8cbc/32.png) [@Mr\_Downtown](https://boards.straightdope.com/u/Mr_Downtown)\ **Post date:** [January 30, 2020, 5:07am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/56 "2020-01-30T05:07:53Z")
> [@Senegoid](#): > > Did you get a close-up enough view to see how those extra keys were marked? No, I had to freeze-frame to confirm that it really was a 16-key set. I’m just wondering where the prop house would have gotten such a thing. Perhaps some Southern California military base put a bunch of old “land line” phones into a surplus auction in the last five years, and the young prop buyer didn’t realize there was anything odd about them. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [January 31, 2020, 6:43am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/57 "2020-01-31T06:43:53Z")
> [@MarvinKitFox](#): > > Do you **really** think it would be easier to remember “QpTXd” > than “555-1047”? YES! In some cases. I used to construct pseudo-words for phone numbers. Once I got a call from a girl wanting a date who knew my number only because the pseudo-word I’d given her (pencilless) was much easier to memorize than a 7-digit number. (I still remember a few of those pseudo-words decades later. Reversing the one that led to a date I see 7 digits that don’t look at all familiar.) It’s hard when the number has a ‘0’ or a ‘1’. Even without those digits, odds are slightly against finding a good pseudo-word. To make it a “controlled experiment” I chose some real numbers (that don’t connect to me) from my phone’s list and get: 887 2535 Turage-J 355 3426 Ekleham Those pseudo-words aren’t good enough to bother with. _Yet even those failed pseudo-words are easier to memorize, IMO, than the 7-digit numbers._ ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 31, 2020, 10:56am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/58 "2020-01-31T10:56:10Z")
> [@septimus](#): > > YES! In some cases. I used to construct pseudo-words for phone numbers. Once I got a call from a girl wanting a date who knew my number only because the pseudo-word I’d given her (pencilless) was much easier to memorize than a 7-digit number. (I still remember a few of those pseudo-words decades later. Reversing the one that led to a date I see 7 digits that don’t look at all familiar.) > > It’s hard when the number has a ‘0’ or a ‘1’. Even without those digits, odds are slightly against finding a good pseudo-word. To make it a “controlled experiment” I chose some real numbers (that don’t connect to me) This isn’t the same because you have three letters for each digit to choose from. If the alphabet were chosen then it would be random letters. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [January 31, 2020, 12:48pm UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/59 "2020-01-31T12:48:37Z")
> [@Senegoid](#): > > My phone has four rows and four column. The fourth column has two special-purpose buttons (redial and mute) and the other two positions have little slide switches. One switch turns the ringer on or off. The other selects tone dial or (simulated) pulse dial. [Like this](https://qph.fs.quoracdn.net/main-qimg-70947c1406f43750607e9363dc9f794d-c)? I seem to remember having an old phone in the 80s that had a tone/pulse toggle, but it was on the bottom. It was a classic 12-button desk phone in the same form as above (minus the 4th column), and if you changed the switch to “pulse” every time you hit a number you would hear a corresponding number of audible clicks from the receiver. The call still went through either way, and I believe it still would today. ETA: I don’t remember whether it still worked if you didn’t wait for the clicks to stop before entering the next digit. On an old rotary phone, you _had_ to wait just because of the way the dialing a rotary phone worked, but I don’t remember if the push button phone described above would make you wait, or if it would just “catch up” if you dialed it like a tone dial phone. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [February 1, 2020, 7:39am UTC](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905/60 "2020-02-01T07:39:16Z")
> [@Senegoid](#): > > My phone has four rows and four column. The fourth column has two special-purpose buttons (redial and mute) and the other two positions have little slide switches. One switch turns the ringer on or off. The other selects tone dial or (simulated) pulse dial. > [@DCnDC](#): > > [Like this](https://qph.fs.quoracdn.net/main-qimg-70947c1406f43750607e9363dc9f794d-c)? Yes, exactly like that. It’s the same model – AT&T 100, except mine has the Lucent name and logo instead of AT&T. And yes, it’s the same color. I never tried using the pulse dialing to see how it works, or if it works. Perhaps I will someday soon. If it works or not, that depends on if the local phone company (AT&T) still supports that. I doubt that the phone will buffer up type-aheads though. I’d be surprised if it does. ETA: Oh wait. My phone doesn’t have the word “TONE” on the \* button. What does that mean? [Previous page](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905.md?page=2) [Next page](https://boards.straightdope.com/t/is-or-was-there-anything-inherently-numeric-about-phone-numbers/846905.md?page=4)