For some time, the Droid Eris on Verizon Wireless has had a bug that causes the user to be unable to hear the person on the other end during a phone call, and/or be heard by said person. A member of the Verizon Wireless forums, after receiving Maintenance Release 4, is reporting that the issue appears to have been resolved with the patch.

The update comes OTA and will reach most users in the coming weeks; however, you can download a signed zip from Google directly as well to get the fix right now. 

To install, place the file on the root of your SD card, reboot your phone into recovery mode, and use the install update button; your Eris should automatically find the file and proceed to flash the update. If you’re running a custom ROM or are on a rooted device, you’ll have to wait for your respective developers to integrate this update into their modifications (unless you want to flash to stock and then update).

Credit: AndroidCentral