There was a post that came out last week on this.....
http://forum.androidcentral.com/motorola-droid/1247-call-quality-static.html
Here's another good one....
http://forum.androidcentral.com/motorola-droid/1633-phone-quality-problems-what-about-you-2.html
It's mentioned that it should be addressed in the December 11 update.
Sure hope it fixes the static on voice calls, this is my second Droid
To get into the programming menu, from the call screen, enter ##PROGRAM and press send. Enter code 000000.
In option 04, you can change the vocode option to EVRC-B, or 13K, it made my in-call audio sound better. Your phone will reset after you exit and apply the new setting. EVRC-B is the newer standard of the three settings.
Warning: Be careful what options you change in the programming menu, you could potentially brick your phone.