Very quiet auto drinker needed

[Gluttonforpunishment]

Can anyone recommend an automated stable drinker that is "silent" or really quiet when it refills?

One of my girls is petrified of one that make a hissing noise, I've tried everything I can think of to introduce her to it gentley but she's not having any of it.

 

[Musto]

Oh.. I've one of those horses. Never found a solution, so bucket of water is where I am now - even though there is an automatic drinker in her stable. Has a total hissy fit if the drinker starts to fill up.
Interested to see if anyone has a solution!!

 

[Pedantic]

I hate drinkers who slawmm all over you and are loudly saying how much they luuuuuuuurrrrrrrrrvvvvvvvvveeeeee you

No sorry, maybe a pressure reducing valve fitted to the inlet of the auto drinker to reduce the pressure, less pressure less hiss.