Listening to Yesterday: A Datum Reverberation

Tuesday at noon, south of San Francisco

  1. a municipal siren
  2. its absence


I didn’t hear the Tuesday noon siren yesterday in San Francisco. I was, however, on the receiving end of a digital echo of the siren — a signal relay, a datum reverberation.

I was driving north at the time from the South Bay, where I’d had an early-morning meeting in Palo Alto on a project. Of course, I knew it was Tuesday, and I knew that since it was Tuesday the noon siren would be going off on schedule some 40 miles north, but that doesn’t necessarily mean that on Tuesday at noon I thought, “Oh, somewhere you can hear the siren right now.”

The Tuesday noon siren is many sirens, over a hundred spread around San Francisco, all part of the Outdoor Public Warning System. First there is the siren itself, and then a spoken explanation that begins, “This a test. This is only a test.”You rarely hear just one siren. Either you are between two or three of them, or you hear one and its echo, its echoes, bouncing off buildings and traveling down corridors. At times you don’t know if the “secondary” siren you hear is an echo, or another siren the sound of which has traveled a further distance, thus delaying its reception. The echo of the Tuesday noon siren is as much a part of its received sound as is the siren itself.

At 14 minutes after the hour, I was made aware of the weekly siren event having occurred when a tiny little icon (a bold, capitalized “IF”) appeared at the top of my phone, which runs on the “stock”Android operating system. I use a popular service called IFTTT (“if this, then that”— the name brings me back to my teen years spent programming in BASIC) to do a lot of micro-tasks, like backing up my tweets to a Google document, and alerting me on the increasingly rare occasion that rain might fall from the sky, and auto-posting my Instagram images to my own website.

Among these IFTTT-enabled tasks, I have an automated tweet set for Tuesday at noon. At that moment each week, IFTTT triggers on Twitter a link to a SoundCloud recording that I made several years ago of a fairly low-fidelity recording of the siren. This sound-tweet isn’t annoying to people; it doesn’t automatically play a sound in their Twitter feed: They need to click on it to hear the siren.

Yesterday at a quarter past the hour, as I drove north on Interstate 280, my phone was displaying a map of the route home. I know the route by heart, but use a map service to alert me to delays due to accidents and, in this rapidly metastasizing region, construction. A little vibration told me that something had occurred. I glanced at my phone, and saw the little “IF” along the top bar (note to iPhone users: this is where Android notifications appear). I didn’t need to click on anything to know what it meant. Also, I was driving, so I wasn’t about to click on anything. With one exception in addition to that rain alert, every IFTTT trigger I’ve programmed results from something I have, myself, just done in person. Tweets are auto-archived right after I tweet them. Instagram photos are syndicated right after I post them. In those cases, the little “IF” is less an alert than an annoyance, telling me something I already know. The exception is the automatic tweet of the Tuesday noon siren. I was reminded at that moment, driving up 280, that it was Tuesday, and that the siren had rung. I looked at the time. The clock read 12:14.

I experienced the siren at a time delay, because IFTTT doesn’t happen automatically — well, it happens automatically, but it doesn’t happen instantaneously. So it was that a quarter after the hour, the news of the siren finally got to me, as I was driving north, about halfway back to San Francisco from Palo Alto. The sound itself had long since evaporated over the distance. The sound never would have reached me, at that point some 20 miles sound of San Francisco. The subtlest of recording devices could not likely have heard the siren from where I was. But I like to think that the siren had faded from sound into data, and that it finally reached me as a tiny little signal on my phone. The fidelity was non-existent, but the arrival of the signal was a simulation of the delay effect that is inherent to the actual Tuesday noon siren’s municipal charm.

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