1920 Hz in my case. I had tinnitus after I got rear-ended at a stop light. Decades later, it still recurs once in a blue moon, lasts for a mere 10-15 seconds then vanishes when I tell myself repeatedly "nothing is playing 1920 Hz".
When I worked for Daimler, I was surprised to learn that all of their cars ship with something called "PRE-SAFE Sound" which, when it detects that you might be in a crash (i.e. at the point when the seatbelts are pre-tensioned), it plays a loud-ish burst of white noise through all the speakers, triggering your ears' automatic response which disconnects your ear drums. This means that when the actual (very loud!) crash happens, your hearing is saved. They developed this in the 90s when, after the advent of airbags, they saw that most injuries from moderate car crashes were hearing related. (Here's a video with some cool detail: https://www.youtube.com/watch?v=vTmLYY-Z2rc)
I always thought it was a huge shame that 1) this technology isn't required/mandated for all cars and 2) Mercedes doesn't advertise this more
The loud part is not the crash itself, but the airbag deployment; it's as loud as a rifle shot because, fundamentally, it is a rifle shot. That's bad in open air; it's way worse in a confined space where that pressure is going to persist for a much longer period of time.
The combustion gas needs to fill the airbag coincident with your face being mashed into it at high speed, and mechanical suppressors slow down the gas so that won't work; using the acoustic reflex (as Daimler clearly does) to get that extra 15 dB of protection means the difference between maximum safe exposure and permanent damage.
I'm surprised that this sound doesn't start playing right before the similarly-explosive pretensioners are fired, since they're also pretty loud, but perhaps they figure it's part of the way to prompt the reflex.
Any idea how many peoples' hearing has been saved by the type of technology?
Not trying to minimize your issue, but is it really still considered tinnitus at this point? I ask because I've been getting this regularly, probably on a weekly basis. It's not a big deal, because it also lasts for only 5-15 seconds or thereabouts, but I've never considered to actually call it tinnitus.
How do you measure that?
My tinnitus frequency is higher than anything I can actually hear so that doesn't work for me.
Since tinnitus uses different mechanics and pathways, that seems plausible.
For comparison, think of a recently blinded person still dreaming visually. Or think of phantom pain.
IANAD, is there any kind of "gain correction" theory for tinnitus? ie, the brain notices your ear can't hear this frequency very well, so it pumps up the volume ... maybe too much.
That would fit this data point, at least.
Weirdly, maybe not so different than when a hearing aid starts ringing.
I've heard this theory. Apparently weak stimulation of the nerves prevents some people's tinnitus.
For instance, if someone couldn't hear a certain frequency because the corresponding hair cells in their ears were damaged, they could still have tinnitus at that frequency arising from parts of the brain that process that frequency.
Tinnitus isn't caused by actual waves of air pressure on the eardrum. We'd not call that tinnitus (unless it was actually inescapable, eg. a perception of rushing blood flow), that's just an annoying real-world sound.
Hearing is connected to eardrum vibrations by a complicated system of the outer ear, eardrum, tiny auditory bones, the fluid-filled cochlea, tiny hair cells with sensory neurons, the auditory nerve, and eventually the brain.
When all these work properly, the brain gets accurate information about sound waves.
When those hair cells are damaged (or wherever the stimulus arises) to send bogus information up the auditory nerve, the audio perceived by the brain as a result of that stimulus is not necessarily correlated to any accurate frequency data that could make it through that pathway.
I experimented real quick and wasn't able to do a great job estimating half of a frequency from playing with the slider on the lower one. Wasn't _totally_ off, but nothing magical seemed to happen when I got to half.
Also, interestingly, since I started focusing on this it has gotten less intense.
I also notice in general that it's much more pronounced after I've been wearing earbuds, even if the volume is turned way down.
I'm not trying to be facetious, genuinely curious.
An incredibly high frequency sine wave noise almost inside my head.
I remembered when I was younger (a long time ago - early 80s) that I used to be able to “hear” when a computer CRT was on in my school computer room (uk, so BBC micro, with the standard monitor).
Ultimately I figured out I could hear the switching frequency of poorly designed / made power transformers.
specifically 110/220v to 5v or 12v transformers and cheap USB outlets.
I spent a day up close and personal around all my power outlets and now my head is clear of that super-sonic ultra high frequency nightmare.
However, then I decided to check if my phone could hear it, so I fired up my DB Meter app. And funnily enough, there is a little spike right around 12kHz, which seems to be right around where my tone is. It's not a huge spike, but it's definitely there.
Weird.
Unfortunately, that frequency is a pretty accurate comparison to my now ever-present tinnitus. It’s not fun.