4 Hz clean pure sine wave BASS TEST TONE frequency 

I more feel it than hear it, although that feeling is translated into hearing, but only be

This is the lowest tone I can detect while not cranking my sub up enough to get distortion. If I crank it up enough so that I can physically feel the pulses I get overtones I can detect even lower than this, but I'm not hearing the tones themselves. I find it odd that I can pick up these sounds because I've done a lot of things that should damage the hearing over the years and I even have mild tinnitus from it. I can also hear the mosquito noise that people my age aren't supposed to be able to hear in the higher register, although I can't hear it at low volumes like my children can. When people with those really big subs in their cars drive through my area I can hear these sub 20 Hz tones from many miles away even in dry air. I'll ask others if they can hear it and they never can, but they'll notice if dishes or something else inside the house vibrates when they get close. I don't understand how a person could sit inside a car with it that loud. I feel this in my chest as well and it gets more intense the louder it is. When the air is moist and cool I can hear other sounds like their engines and tire noise just as far but that's rare. It's basically only when it's foggy out. If they drive by late at night it drives me crazy. It'll wake me from a dead sleep sometimes if they have it cranked loud enough. I doubt the people with these in their car can hear it because it is so obnoxiously loud to me and I'm at least a few hundred yards from where the main traffic goes through. The normal higher register tones that music is played at are much lower in volume on their systems. They must just like the feeling.

Connected to deep earth space 9 come in: ...

Sound like intro from Rambo 2..

You can count the frequency

I want to understand the research on this. Does this help ptsd or anxiety? I do feel this in my forehead.

All I hear is a person having a heart attack as I listen from the outside. Also apparently this frequency is supposed to make you feel fear