I don't think we've been taking this subject seriously enough. Look what I found on a Google search:-

"What happens when you hum against the comb? What kinds of sounds are you able to produce? How do your lips feel? Are you able to feel the vibrations? When you blow harder, does the speed at which your lips vibrate change? Does it tickle more? Less? When you place your thumb on the comb does it change the sound? What might cause the difference? Identify the force and source of energy you are using to produce the sound. " I can't get the vision of hundreds of bearded, kilted men (and women) wandering around Stonehaven exclaiming "Och, ma lips tickle!".

I'm off to bed. Night all.

LFF