Why the modems screamed

In The Atlantic, Alexis Madrigal recalls the otherworldly howl of a 56K modem negotiating its connection, and quotes our pal GlennF in his 1998 explanation of that characteristic anthem of the heroic bronze age of the Internet:

This is a choreographed sequence that allowed these digital devices to piggyback on an analog telephone network. "A phone line carries only the small range of frequencies in which most human conversation takes place: about 300 to 3,300 hertz," Glenn Fleishman explained in the Times back in 1998. "The modem works within these limits in creating sound waves to carry data across phone lines." What you're hearing is the way 20th century technology tunneled through a 19th century network; what you're hearing is how a network designed to send the noises made by your muscles as they pushed around air came to transmit anything, or the almost-anything that can be coded in 0s and 1s.

The frequencies of the modem's sounds represent parameters for further communication. In the early going, for example, the modem that's been dialed up will play a note that says, "I can go this fast." As a wonderful old 1997 website explained, "Depending on the speed the modem is trying to talk at, this tone will have a different pitch."

That is to say, the sounds weren't a sign that data was being transferred: they were the data being transferred. This noise was the analog world being bridged by the digital. If you are old enough to remember it, you still knew a world that was analog-first.

The sound clip comes from The Museum of Endangered Sounds, where you can find "the mechanical noise a VHS tape made when it entered the VCR or the way a portable CD player sounded when it skipped."

The Mechanics and Meaning of That Ol' Dial-Up Modem Sound (via JWZ)


  1. Ah, the memories. Sitting in by high school’s library, checking my e-mail on the local Board of Jewish Education’s free BBS. They connected to The Internet to exchange messages twice a day. High tech!!

  2. I miss that sound.

    Now I just turn on my computer, and the internet is just *there.* The technological wizardry has been obscured by how easy it is. Everyone’s on the internet, including companies who are selling streaming video. Sometimes I want to spend an hour downloading a short .mp3 file just so I can feel like I’m doing something special again.

    1. Someone should create a simulation of what it used to be like. It’s like using an emulator to play all the old ZX Spectrum games, and realising in about 30 seconds that most were crap.

  3. Numbermuchers!!!

    He is totally missing the sound of old hard drives…like that Conner 120 meg that my friend had.

    1. Loved that disk.  Loved it right up until about four months ago, when it got thrown out by mistake while traveling.  Moral of the story: don’t let being in a hurry tempt you into wrapping valuable things in packaging that looks like trash. :(

      What kind of people are we?

      1. Did anyone figure out the number that was dialed using the informatiion in that link?

        Could just play it while holding your phone to the speaker too.

    1. I remember figuring out the AT command that lengthened the allowable gap in signal so that this didn’t kill the connection.

  4.  Please lets not forget, this screeching sound is still commonplace in many rural areas of the U.S. We were finally able put our trusty U.S. Robotics out to pasture only a few years ago.

    The free market hasn’t yet seen fit to bless its widely-dispersed constituents with modern services.

    1.  Problem there is lack of a free market.  US telecommunications may well be the purest example of a badly regulated marketplace ever.  Good regulations create and maintain free markets (despite pseudo-libertarian and neo-conservative laissez-faire nonsense) just as bad regulations create and perpetuate corrupt marketplaces.

  5. The article refers to a 56K modem, but I remember the first few seconds being what I also heard back when I got my first computer and would dial up strictly local BBSes (Citadels were my favorite). That modem maxed out at 1200 baud.

    It was slow, clunky, and text-only, but I met a lot of great people that way, and because I was limited to local calls it was easy to start talking to someone on a BBS and then meet them in person. In fact I met my wife that way. 

    1. Yeah, one of the memories this brought up was the progression in the handshake back from 300, to 1200, to 2400, to 9600, etc. I believe the shorter handshake is why ATMs use (IIRC) 1200bps modems to communicate with the mothership.

      1.  Similarly, back when stores used modem dialup to do credit card authorizations, they used 300 baud because it was faster to sync up the modem at 300 (which took about 2 seconds) and send the 100 characters or so of data in 3 seconds than to spend 45 seconds syncing at 9600 baud to send the data in 1/10 second.

        There was a band called “Information Society” who had a piece called “300bps 8N1” – you could play the tape into your modem and it’d give you the lyrics as text.

  6. I don’t need recordings to know what a VCR tape ejecting or a CD skipping sound like.  I also remember what rotary phones and a cassette tape in the process of being eaten by the deck sound like. 

    I must be super old.  :-(

  7. I was trying to play… heretic?  hexen? whichever came first, with a friend over modem, and something bugged out and set the baud rate to a negative number.  I got to hear the modem screech drawn out over about 5 minutes.  Was a pretty good illustration of how it worked.

  8. I recall for a while, sometime recently after switching from 14.4 to 56k, the screeching would usually be interrupted by two distinctive “BONG” sounds.  I never did figure out exactly why it did that; it doesn’t seem to have been a universal part of the experience.

  9. The bong sounds are I believe a waveform to help detect bad frequency ranges which can then be marked-bad and ignored and would be why you get a lower BPS rate than both modems were otherwise capable of.

    I’m also pretty sure that this annotation is incorrect. The blocks listed as connection accepted and throughput were most of the time not there and I’m quite sure they were a renegotiation of sorts caused again by connection issues. I don’t have any scientific evidence of this though it’s just my experience from being sat next to my 4 line BBS for several years (that always had the carriers on).


  10. You don’t use rotary phones anymore? Are you serious?

    (Sorry for the crappy picture, can’t find the camera.)

  11. I wish I was young enough to NOT remember goddam dial-up.  Slow… slow… slow… hell.

    1. If only somebody had thought to make the images load from the bottom up.

  12. I had to do this not more than a few weeks ago!

    Signing up for an Apple developer program from India, it appears, involves sending a fax to a particular number, and then calling up to pester them to follow up. Let me repeat that again: I actually communicated to Apple Computer in 2012 over fax. No, I have no idea why they couldn’t just take my payment online… They allow that for App Store purchases…
    I always knew that the initial handshaking tones indicated the speed; 9600 sounded different from 14.4k, 33.6k or 56.6k… I used to disconnect immediately when I knew that it was only at 9600k or less, and try again a few seconds later, before the system billed my net account! Old times! How I don’t miss thee!

  13. Over 300 baud you can’t whistle the connection sequence into the acoustic coupler any more.

  14. Spent many many years dialing up at 2400 baud.. if it could have connected then played the James Bond theme it would have been just like using Telemate again to dialup local boards. Like the crazy guy who ran a C64 BBS on a 300 baud modem just for kicks while everyone else was venturing into dedicated lines and multiple nodes.

  15. There is a scene in the movie “Men in Black 3” (Yeah I watched it last Monday, twasn’t very good), where the young version of “K” is trying to use an early version of the mobile neurolyser mind wiping device. As he is trying to use it it makes the modem connection noise, which did made me smile. I immediately thought, “why is this thing trying to connecting to something”, but then later thought it was a bit of a clever reference to older obsolete technology and the movement from analog to digital. Kids would be unlikely to get it, but most older folks should, if only to identify it with old technology no longer used. Anyway I thought it was a bit clever and funny (unlike most of the movie, though it had its moments).

    Considering the name stood for MOdulation/DEModulation it should be one of the more obvious vestiges of the analog age.

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