I have not a clue... but I'll bet there is someone who does at: http://www.chiffandfipple.com/

I play whistle, but not so well as to be appropriate for amplification. A whistle MUTE on the other hand, is an item which my neighbors, family and dogs might be interested in...

I've long considered the whistle one of those "au naturale" instruments like the Great Highland Pipes, Bugle, Fife and Drum which need electronic enhancement about as much as Dolly Parton needs a breast implant. But then I like to play a gut-strung parlor guitar by the light of an oil lantern or my whistle from a canoe in the middle of a Maine lake at 0530 and confuse the bejeezus out of the Loons, too. So stay tuned, Pilgrim; someone who knows a whole lot more about these things than I will be along presently to enlighten Thee. };>{)