I was chilling at home when out of nowhere this loud shriek started blasting.<p>just pure sine wave as loud as a fire alarm next to your ear.
I cannot even describe the confusion of that moment.
it was like a glitch in the matrix.<p>fast forward a bit - I opened a spectogram app trying to locate the source of the sound but shockingly my entire living room, at every corner from floor to ceiling, rocked a solid 1306hz sine wave at >80dB clocking 87dB at max measurement.<p>a quick search online suggested permanent hearing damage at prolonged ~85dB, which is wild.<p>I'm not sure if it was the frequency or the amplitude but whatever it was about that sound was just impossible to locate with the human ear.
it just sounded "in your head" everywhere you go.<p>after recording this sound and playing it back on my phone I ruled out neurological cause, so the only reasonable ideas I had left was something electronic bugging somewhere.<p>I disconnected my laptop, monitor, tv, turned off the AC and the lights, heck I cut the power to the entire apartment and yet the sound continued unbothered.<p>could it be something battery powered?
helpless and dumbfounded I even started moving the electronics to another room and yet the sound remained.<p>I even checked other apartments but nothing came close. it was like a UFO in my home.
at one point I even half jokingly suggested to my friend it might be Havana syndrome type of thing.<p>the sound persisted for a minute and was gone.
then it rang for another minute and had me baffled.
finally it repeated for a third time...<p>I gave up. I went to check if I could block it by playing music on my headphones and... a shriek right in my ear!<p>IT CAME FROM MY HEADPHONES?!<p>it seemed whenever I touched a certain spot I could control the sound.
wiggle a bit to the left and it stopped.
a nudge to the right and it would run circles at an apparent rate of 1306 times per second with the force of not less than 1000 suns...<p>APPARENTLY my noise-cancelling headphones were on and its internal microphone had broken, giving it a false signal which it tried to cancel... by overcompensating to the max.<p>turning off noise cancelling appears to stop the noise completely.<p>so essentially my headphones broke into a megaphone.
(well, at least one which also has a broken microphone)