I have tried it and for me I can only notice that my attention has drifted after it has drifted. I've never noticed that my brain is currently trying to turn an auditory signal into a meaningful symbol (symbol is probably not the right word). I only notice that I heard a dog bark.
after meditating regularly for a while, doing a noting practice produced a distinct shift for me on this point. I realized that most of the time, when I hear a sound there is also a momentary "shred" of visual/muscular thought that accompanies it. for example, when I hear a crow, there is a bit of black/feathery/tree-branch/etc. if this is interesting, you can find instructions from Shinzen Young online.
typing this up, I realize I'm not totally sure to what extent this is something that was happening before the practice vs something that developed from it [i.e. less habitual energy spent blocking things out], but either way I recommend it :)
I have tried it and for me I can only notice that my attention has drifted after it has drifted. I've never noticed that my brain is currently trying to turn an auditory signal into a meaningful symbol (symbol is probably not the right word). I only notice that I heard a dog bark.