Check out http://www.bbc.co.uk/dna/h2g2/A486074, look up the Low Whistle entry 
If that didn’t suffice see http://www.bbc.co.uk/dna/h2g2/A301852 lookup Modern Times entry about the flageolet vs. recorder 
This BBC site pretends to be The Guide To Life, the Universe and Everything. Unfortunately. maybe, if it was written by the Depressed Misanthropic humanoid (is it Marvin ?), and edited by the Wedgeworth teapot-making coffee machine.
It’s below the level expected even from the infamous Encyclopaedia Galactica, let alone a Hitchhiker’s Guide to the Galaxy.
I expected better from 21st century BBC than this piece of Encyc-limey-dia Anglicana.
Ahh, and I thought I was the only one here who remembered the Hitchhikers’ Guide!!! 
You are not alone! Our car’s reg number is VOG … so is universally referred to as the Intergalictic VOGon Starship.
Improbability factor 20,000,000,024 to 1 and falling…
Think about this: If Ford had a tin whistle in his satchel it would have been the second most useful item (after the towel, of course)
Uses: Whiling away time in a Vogon hold or on the bridge of star cruiser, annoying Arthur (and Marvin), busking when cash was low, and a D whistle in the third octave could probably qualify as a weapon.
Well, The Vogon captain might not have liked Whistle music, you know… But then again he (Ford or Arthur) could have played a background score to Ode to a Small Lump of Green Putty I Found In My Bellybutton While blablabla…(I can’t recall the whole name of the poem) It could have saved them!
um…Erm…But then again, if that happened we never would have had the story, right?