North of the Border
I think Paul Sellers preaches about listening to the sound of planing or skipping, among other things, as feedback. I, for one, never ever rely on sound because the minute I step in the shop, the music is on. What works for others definitely may not work for me.

Whether I am using a chisel, saw or plane, I can easily tell if the edge needs a honing: ie if the tool becomes much harder to cut. If so, I will check the edge by feeling it with my finger and then I can decide if I need to do a quick hone -- which will take a couple of minutes in most cases as I don't usually wait till an edge dulls a lot.

I will look at the edge and feel it or slice a piece of paper to confirm it is super sharp only after I give the edge a total sharpening.