Aastra has announced that the 67xxi series phones will all now support their Hi-Q (which uses the G.722 Codec) audio via a free firmware update. All you need to do is update to an Aastra 67xxi firmware version of 2.5.0 or later. Once the phones are configured with this update they will automatically negotiate the use of the G.722 codec when available.
For those of you unfamiliar with G.722 it is becoming quite the popular codec to use over G.711 when bandwidth is not an issue. The G.722 codec offers significant improvement in speech quality as the bit rate is higher and there is less compression involved.