I Miss the Dial-Up Modem Sound

I Miss the Dial-Up Modem Sound
Graphic: Gizmodo (Photos: Wikimedia Commons)

If you were born after Wi-Fi, the dial-up modem noise is what electronics used to sound like: dated, from the era of the fax machine and the non-customisable ringtone. To me, it’s more than that. The sound symbolises the limits of what whole generations had agreed was basically tolerable to get online.

Like 1950s suburban commuters idling on a new interstate highway, millennials spent an inordinate amount of time stuck waiting in internet traffic. How many hours (days? months?) did we all wait to connect to the internet, for pages to load, for videos to buffer? Shared, inane frustrations like these give life texture. I’m not nostalgic for a slow connection, abruptly cut off whenever my parents needed the phone. It’s just that I remember the modem sound so vividly — a futuristic racket engrained in the collective daily grind.

The modem noise lasted for 19 seconds — six times the maximum duration the average internet user was willing to tolerate for a page to load in 2016. The wait was worth accessing the World Wide Web — each time, a wondrous event. As a seventh grade all-girls’ school lifer, I could talk to boys, and subsequently exchange tales of the previous night’s AOL activity in class. We formed generational lingo like “lol,” painfully acclimated to ghosting, explored the freedom to say things otherwise too terrifying to vocalize in person. I could lurk in the sleazy alleyways of chat rooms where some guy was always streaking through screaming “PUSSY ARSEHOLE BITCH!!!!” (New vocabulary!) The internet was a homier place where we needed analogue names for everything, like a “room” or the “castles” and “domains” of Geocities. We could breeze through assignments, feeling pretty smart tossing little bits of Cliff’s Notes and Jeeves answers into papers.

I didn’t care much about the mechanics of getting there, and before writing this, whatever the phone did during the dial-up process remained a total mystery. What was that sound, and why could I hear it?

What Does the Modem Dial-Up Sound Mean?

I’d been under the impression that the phone was talking to a modem — the sound opened with the dial tone and touch tone keypad. No: a phone did not talk. It just overheard and transmitted a conversation which took place between your modem and a modem elsewhere which connected us to the internet.

The modems cleverly used the phone lines for their own design, a vast and convenient superhighway for information dispatch. The network already connected households across the world, so it made sense for modems to mimic the phone’s transmission medium, sound, in order to communicate. The phone and modem was a charming combination of a soon-to-be obsolete technology and the new, sort of like powering an HD video camera with a wind-up Bolex crank.

Still, what was the point of allowing us to overhear it?

Finnish computer scientist Oona Räisänen, who has translated the entire conversation, observed that if the sound was audible, a human would be able to tell it was the wrong number — say, if you’re dialling someone’s home phone over and over. “If you happened to dial a number that was not in use, or it had an announcement, or someone other than a modem answered, or your dad was talking in the upstairs extension, you would hear it right away,” Räisänen explained to Gizmodo.

Räisänen’s well-circulated 2012 spectogram shows the entire conversation dissected to fractions of seconds. The process can be found here, but in my dumbed-down terms: the modem hears the dial tone and dials the number. The line falls silent for a nail-biting two-seconds, and then (if all goes to plan), tweets and trills with the modem on the other end. This is the “handshake”: the other modem saying hi, then the two modems agreeing upon the protocol, or, the format in which they should exchange data (sort of like settling on a common language).

Another pause, followed by solo beats resembling a softened smoke alarm. This is the other modem disabling the echo suppressor — the telephone’s mechanism to temporarily silence the listener’s end so that our own voices don’t come back through the receiver. The modems start up a chorus of high-speed peeps and warbles, which is them getting more granular about how to best communicate with each other at certain frequencies and request to modulate power. Finally, the wall of static, a high-speed transfer of binary. As Räisänen describes it, the modems transmit scrambled data to “learn how the other modem sounds over the channel.”

Listening and interpreting begins to feel like translating bird song. The longer you scrutinise, the more it makes sense that developers use the word “talking.”

This went on from the 1950s until the aughts, until the phone system hit its limit when connections strived to grow faster, Räisänen said, adding that there’s a theoretical limit (the Shannon limit) on the speed at which speech frequencies can transfer data.

Now a safe distance from dial-up days, most of which were before my time, it’s fun to romanticise early modem listening as a folk ritual. In an email to Gizmodo, Kevin Driscoll, professor of media studies at the University of Virginia, described early modem listening as a participatory act of summoning the technology to do its bidding. The old acoustic coupler modems, used through the ‘80s, required humans to manually dial the number and place the phone headset onto a specialised cradle with an earpiece and speaker, with rubber cups to block out ambient noise. They’d wait for the modem to chirp on the other end, and your modem could “speak,” human-like, directly through the telephone. (Here’s Matthew Broderick hooking up a later model in WarGames.)

But if they misdialed — which, Driscoll recalls, was pretty common — they apologise on the modem’s behalf. “When dialling by hand, you’d just say ‘oops! sorry, wrong number’ and hang up,” he said. “But if you were ‘auto-dialling’ with a direct connect modem and you got the wrong number, you’d hear the sound of the person on the other end yelling through that little speaker — ‘STOP CALLING THIS NUMBER!’”

“So,” he added, “early modem users learned how to listen to the sounds of modem.” For this reason, he said, even direct connect modems where users would dial from the computer, would generate the sound. “If you couldn’t listen to it dialling and connecting, how could you be sure that the modem was working?” In one, extraordinary circumstance when modem sounds faintly leaked into an adjacent phone cable, a virtuoso ear on the phone receiver could divine faint, overheard doots and static as a user typing messages or playing a particular computer game.

We’ve lost the dial-up sound to a trove of bygone minutia too roundabout to explain while we were busy hurtling toward a frictionless future. But isn’t that something, listening in to the scrambled murmurs of a computer game hopping over copper wires running through the walls? Vivid memory is like that — walking in and eavesdropping on the past.