Gingerbread brings lots of nice spit-and-polish features to Android such as it’s screen-off animation and an excellent keyboard. One of the non-critical but quite annoying downsides to running Gingerbread is a 2-3 second delay at the beginning of voice calls where the remote caller cannot hear anything, originally thought to be device-specific with the HD2 and Nexus One. The problem was later discovered to affect all Gingerbread devices. This fix reduces the initial delay from 2-3 seconds to under 1 second.
A new patch made available at XDA by temasek to replace libaudio.so in the Android system libraries has been reported to eliminate the problem. This fix is said to be most compatible with CyanogenMod and Android OSP ROMs, with at least one user experiencing a no-boot situation on a different ROM. As a result, a full nandroid backup is recommended so that a restore is possible in the event your device won’t boot after applying the patch. The fixes were submitted upstream to developers at CyanogenMod and should be fixed in the latest nightly releases, and is expected to be merged into the 7.0.4 release.