White noise generator ?

I've been asked to protect a meeting room against audio recording.

I am wondering if white noise generator is an efficient solution : is it possible to filter this noise afterward ? is it not annoying to the hear ? etc.

What do you think of this kind of product :
http://www.soundmasking.com/PepPack.html

what do you think is the best (quality/price) product available ?

thank you for your help !
Jef