I have SO been thinking about this lately. Haven't done it, would love to try it. That's as a lee.
As a ler, I'd love to get some kind of headphones on my lee that block all sounds except for my voice, like from a microphone or something. I think that would amplify that verbal aspect of it all really really well. I could literally whisper right in his ear while tickling. YEE BUDDY!
I've often been tickled with a blindfold, and it heightens the surprise and the sensation (as long as the ler keeps going to different parts of the body).
I've only been tickled with the blindfold and earplugs a few times. The earplugs don't add to the tickling sensations for me, and subtract the verbal taunting that I like.