Good news for European Android users. Sony has confirmed that HD Voice is available on the new high-end phone, the Xperia T. Though not listed on the product specification page, Sony Mobile's product blog confirmed HD Voice's inclusion on the Xperia T.
Was Sony reluctant to admit the feature? Apparently, in order to get the most out of the feature, both callers need to have HD Voice available. Only a select number of carriers even offer support for the feature (including Three and EE in the UK). Perhaps Sony was concerned that customers would be confused and frustrated in trying to implement the new feature. After all, it's better to surprise and delight customers than frustrate them any day of the week.
From those who have had the opportunity to use the feature, HD Voice is a great improvement over standard call quality. For those who spend a great deal of time on the phone, HD Voice is certainly a feature worth considering.
Source: Android Central