Taking a dB measurement in C weighting over some integration period

Yeah, the non filtering of the lower frequencies happens when done correctly, if I recall. I am curious what that actually is, and I am curious what is making those specific frequencies.

At a certain decibel range of ambient noise, humans become even more sensitive to the lower freqs. Being able to use that knowledge while taking measurements of my own is useful to me.

I would be interested to know the sound signature of gas turbines.