If you want the best call quality on your mobile you need HD Voice
HD Voice gives you crystal clear high definition voice calling without background noise. It’s like talking to someone in the same room, even if the Vodafone Warriors have just scored. HD Voice is also known as Wideband audio.
If you have one of the smartphones listed below and you're a Vodafone customer, you don’t have to do anything - HD Voice is already enabled on your mobile.