I find the bells to be fairly annoying after a while, plus they get plugged up in the snow.  Beepers are nice, but sometimes they echo so much it's hard to tell exactly where your dog is if they're quite a ways away. Maybe that's just me, I don't know. I've gone to the Alpha GPS unit.  Shows exactly where my dog is and vibrates if she goes on point.  Has adjustable vibrate, tone and  shock.  I don't make any sounds at all after leaving my truck to start a bird hunt, or during the hunt.  Between the use of hand signals and the collar we're good to go.  Also, one of the reasons I went to this type of collar is because my dog (5 year old female GWP) is deaf, which throws another factor into the mix.  The system is a bit spendy, but well worth it in my opinion.  I've had too many situations where a pheasant will take off in the sagebrush and run out of sight with the dog close behind!