Comment Re:You can hear below 20 hz (Score 2) 70
20hz is not the level you can hear, it's the level where repeated pressure changes get unified in your brain to a single tone. Below that level, your brain perceives them as individual beats. At 20hz they are coming pretty quick, but if you listen (and they are loud enough) you can distinguish each one.
Something somewhat related to this low frequency sounds are "binaural beats" sounds that purposely generate infrasound. You wear headphones, and one ear gets a frequency, and the other gets a frequency that is shifted away slightly. so the two beat against each other, which produces that third sound.
They presumably get your brain to sync to the infrasound, in relation to the Alpha, Beta, Theta, and Delta frequencies naturally present in the human brain - depending on what the person is doing at the time.
I think they work. Way back in the day, I wrote a program for my Amiga to generate theta waves, and still use the ones on YT while I'm working. I find Theta to be relaxing, and Beta to be annoying.
So I agree with the premise that infrasound can have an effect on people. But that it is very frequency dependent. Some frequencies of infrasound might produce relaxing effects.
However, My guess is that people who "feel" infrasound and think it is a ghost, probably would think it was a ghost if they were in an old dusty crusty house regardless.