What was that terrible non-sound I experienced this morning?

June 5, 2015 8:02 AM

What was the silent "bomb" of a cell phone alarm the couch surfer on the other side of the wall detonated this morning?

Hello audio nerds of Mefi,
The couch surfer sleeping on the other side of the wall from my bed set off an alarm this morning that has me completely baffled.
First off, I know I am not imagining this. I know he's there and sleeps on the couch - his head and mine are very close, with the wall between us. His cell phone is used as an alarm.

This morning, I first heard a vibration or buzzing sound. About 10 minutes later, it wasn't so much a sound as a "spreading sensation" that started in my eardrums/sinuses and went directly to my stomach. Possibly with a "sound pressure" component added. Moments after this "bomb" went off, one of the other housemates came out and told him to turn it off.
Apparently, this alarm woke everyone in the house, despite being nearly silent.

I know it is not the "Mosquito Ringotne". I'm 50 years old and did the online test. I can "hear" that ringtone (even at it's higher frequencies), and the sensation this morning was 1000X more uncomfortable than that. I'm 99% certain it emitted from his cell phone and no other device was used.

Any help with what this was or where to find a download of it would be helpful.

Thanks!

posted by Cookbooks and Chaos to Computers & Internet (11 answers total)

Could the cellphone have fallen into or under the couch and somehow caused a resonance? I can cause my whole bed to shake if my phone vibrates off the side of the bed and falls between the mattress and the frame instead of onto the floor.
posted by books for weapons at 8:23 AM on June 5, 2015 [4 favorites]

The brown note concept has been discredited - but maybe it was some sort of similar low frequency sound?
posted by gnutron at 8:24 AM on June 5, 2015

I was about to suggest infrasound? It's been known to drive humans up a wall. Haven't heard of it being used as a cell alarm, but it seems plausible that an MP3 of it is available and playable via standard smartphone.
posted by julthumbscrew at 8:25 AM on June 5, 2015 [2 favorites]

Response by poster: I will not threadsit:

This was specifically NOT shaking. No movement of any kind, and no resonance.

I know that because the tri-plex we live in has hardwood floors and is raised from the foundation about 3' causing what I think is called the "tympanic effect". I can hear and feel footsteps, doors closing, the bathroom fan and when he drops the phone on the floor next to the wall.

Also, I have Googled this to hell and back and only came up with the youtube video of the Sonic Nausea device.
posted by Cookbooks and Chaos at 8:31 AM on June 5, 2015

Could you ask your couch surfer?
posted by aniola at 8:34 AM on June 5, 2015 [15 favorites]

I'm skeptical that a phone's little speaker could produce that much volume or that kind of frequency. I have to wonder whether the phone's alarm going off coincided with something like a refrigerator or air-conditioner compressor kicking in, and it was that (or the combination of the two) that you were perceiving.
posted by adamrice at 8:46 AM on June 5, 2015 [7 favorites]

Ask, pretty please? Because now we're all curious... and if it's something that can be gotten on a phone, we need to see if the rest of us in the house can stand it enough to wake a particular teenager.
posted by stormyteal at 9:18 AM on June 5, 2015 [10 favorites]

Response by poster: @stormyteal:
I'll do my best - I am never quick enough to catch this guy (and I know it's a guy by the snoring) before he leaves for the day. Maybe this weekend. Updates will be provided here if there's anything new.
posted by Cookbooks and Chaos at 9:32 AM on June 5, 2015 [3 favorites]

Did he leave his phone connected to a Bluetooth-enabled sound system?
posted by ArgentCorvid at 9:35 AM on June 5, 2015 [3 favorites]

A phone speaker would never be able produce low enough frequencies to have this sort of effect. Nor could it produce the required intensity level; the minimum required sound pressure level for a very low frequency to be heard by a human is much higher than for a frequency in the normal audible spectrum.

The sensation you experienced was almost certainly not caused by his phone. It was more likely some sort of anxiety or other perceptual reaction you had to his phone making some kind of normal alarm sounds. Your wall probably acts as a low pass filter, so you may not have completely heard the alarm as a normal sounding alarm.
posted by Lutoslawski at 9:59 AM on June 5, 2015 [2 favorites]

This was probably sympathetic resonance caused by the phone vibrating on top of some hard surface at that surface's resonant frequency, in such a way that every pulse of the phone's eccentric weight amplified that surface's vibrations. Alternately, the phone could have been lodged against something hard in such a way that it created this effect by itself. This can happen if the phone is loosely pinned only at one end (say, by a power cable hanging off the edge of the surface), while the end with the eccentric weight is allowed to move. In this scenario the loose end of the phone basically bounces, slapping the surface upon which it rests.

In either case, once the additional surface began vibrating in sympathetic resonance, that amplified resonance is what shook the rest of the house.
posted by fedward at 11:06 AM on June 5, 2015 [1 favorite]