What I'm really asking is if this is practical to worry about. It makes sense that any frequency could damage your ears if the amplitude was high enough, but aside from crazy ultrasonic weapons, could frequencies higher than I can hear hurt my ears?

I've never had my hearing range tested and part of the reason I ask this question is because I don't want to do anything stupid if I try to test it myself.

Let's assume I can't hear 18khz. Assume I'm listening to a song at a comfortable listening level and then the next song comes on and it's just a pure 18khz sine wave with an amplitude of 0 dBFS but I can't hear it. Would listening to this damage my hearing even if I couldn't hear it? I understand that it could damage my headphones or stereo system but it's my ears I'm concerned about.

I thought of this question again when I was taking lossless files, paralleling them to mp3 versions of themselves, and then inverting one file and mixing them together. This is just a fun thing to do and the resulting mix shows you only what the mp3 is missing. The resulting mix is pretty quiet and I turned it up maybe 15 db to make it louder. But then I remembered that lossless files contain higher frequencies than mp3 files and since this mix contained only what the mp3 was missing, it probably contained a lot of frequencies higher than I can hear. Then I wondered if by turning the mix up 15 db, maybe I turned up those frequencies to dangerous levels. Of course, to me it didn't sound dangerously loud or harsh.

In REGULAR situations such as these, should I be worried about whether frequencies higher than I can hear can damage my ears?

The only thing that could realistically damage your hearing in the context of listening to music is listening too loudly to frequencies you can hear. Just watch the volume level and you'll be fine.

It's generally a bad idea to jack up the volume on difference files, as any sudden musical content will give you ear a nice wallop. Also, just because your ears can't hear a tone doesn't mean your headphones aren't making it, and thus you have no way of knowing how hard you're driving your cans, though I haven't personally heard of people blowing out their drivers with 20kHz tones. As far as the physical effect of ultrasounds on the ear, here's a paper that seems to address the subject a bit.

Most recommendations are to avoid exposure over 110dB. I should clarify that is for frequencies over 20KHz. Your hearing cut off is likely a lower frequency.

Frequencies you can't hear can't damage your hearing. To keep it short.

ruben123 said:

Frequencies you can't hear can't damage your hearing. To keep it short.

Click to expand...

 
Except for sonic weapons.
 
https://en.wikipedia.org/wiki/Sonic_weapon

An interesting article in the September 2015 issue of Scientific American, shows that audiogram tests don't uncover all hidden ear damage.

Hidden Hearing Loss from Everyday Noise

http://www.scientificamerican.com/article/hidden-hearing-loss-from-everyday-noise/