This is great for playing live with when you plug an electro acoustic into an amp, you don't get any feedback which is great if you play live. This is used a lot by Dave Grohl (Foo Fighters) when he does acoustic songs. This works very similar to a gate pedal on an electric guitar.
Forget about that noisy and annoying feedback. Just put (carefully) this item, and go.
As known, it will reduce some high frequencies, but nothing that cannot be fixed with some EQ arrangements.