The post on ear plugs has prompted me to ask a different question related to earplugs.
I have recently tried plugging my left ear with cotton wool at sessions where there are tuning issues going on. It is my perception that this accentuates any issues. Say a guitar a touch flat and a whistle a touch sharp with a fixed pitch box. You know the thing! If it is a bit messy it seems to become easier to pick out say the lead instrument and stay in tune with it.
Anyone else use this trick?
I haven’t used earplugs in an actual playing situation…yet. But I did recently discover essentially the same thing you point out in your post, namely, that using earplugs helps sharpen things up in such a way that makes it easier to hear what you are should be in tune with, and also whether you are in fact playing in tune. I realized this while trying to play along with recordings recently. It led me to experiment a bit. For example, I tried having the recorded music come through headphones while I played along. But what seemed to work best was having plugs in while playing along with the recording.