Very relevant topic. Sorry to be Debbie the downer, but I have permanent ringing in my left ear as a result of hitting an obnoxiously loud driver. For legal reasons I'm not going to mention the OEM. Now, I always wear an ear plug in my left ear whenever I'm practicing drivers or playing, because I don't want it to get even worse. Before I started wearing ear plugs, my ear would ring all night long and I had trouble getting to sleep. I went to an ear specialist and they documented hearing loss.
So, I'm searching for the quietest driver that doesn't totally rob me of distance. So far, I've found the old Callaway C4 to have a nice muted sound. Also, there is a company called Louisville Golf that still makes persimmon drivers. The Callaway C4 is "only" 360cc's and Louisville Golf's drivers range from 195 to 360 cc's.
I would love to find a driver in the 440-460cc range with some modern technology (adjustable, high COR, high MOI), with a low decibel level. Sadly, this will probably never happen until someone wins a huge lawsuit against an OEM.
