Just to be clear he said 6 hours to beat it without dying 😉 (which is commitment!)
The decibel meter is a visual clue to where/if the creature is present, it would be a little too hard to tell where the creature was coming from with just spatial sound.
Im not really sure what you mean that you can barely hear the sounds, this was never a problem through playtests and watching other people play it. Maybe its an issue on your end?
I do agree if you die more than a couple of times it loses its scare factor and it gets annoying, but you can say that about all these types of games. Its partially why we chose it for the game jam "shovelware horror"