The iPhone 5 includes support for new wide-band HD Voice, which makes call quality significantly higher than on previous iPhones and on the vast majority of other smartphones.
In the US the iPhone 5 doesn't take advantage of the new wide-band HD Voice feature, but it looks like it'll be supported when the smartphone launches on EE in the UK. Additionally, HD Voice has also been confirmed as being supported on T-Mobile, Orange and Three.
Essentially, HD Voice increases the frequency range used when making voice calls which makes people sound much clearer than before. For those interested in specifics , previously the frequency range was 300Hz to 3.4KHz and with HD Voice it is increased to 50Hz to 7KHz, which compares to 80Hz to 14KHz in real-life conversations.
HD Voice is one feature which has been widely unreported when it comes to the iPhone 5, but it could be the feature that makes the most difference to iPhone 5 owners . 3G will be sure to report on our experiences with wide-band HD Voice when we review the iPhone 5 shortly.
Three have the best iPhone 5 deals available in the UK right now and enable you to pickup Apple's iPhone 5 with an upfront fee of just £79 on contracts starting at just £34 a month. That gets you 500 minutes, 5,000 texts and unlimited data !