Human beings are superstitious about sound as we are about a lot of things. We claim that we hear things that aren’t actually there. Hearing is a tricky thing and we tend to describe things as supernatural when we don’t have any rational explanations. You should be careful and keep an open mind.
An interesting post:
Are You Superstitious About Your Sound?
There may be apps that do that. You can definitely find spectrum analyzers that will measure ultra low.
Is there an APP that can measure the ultra low frequency levels?
.Plaster is a viable middle and high frequency absorber. We have used it many times in new builds that have…
Hi Dennis I'm curious what you think of acoustic perforated plaster - say CST Galaxy -on particularly ceilings in music…