Vodafone improves call quality with HD Voice

Vodafone customers with the right handsets will notice a dramatic improvement in call quality from today as the carrier launches High Definition Voice.

There is no extra charge for the new service.

NSN country director Andrew Button explains that HD Voice isn’t particularly new. It delivers the same wideband audio that conferencing services and VoIP (Voice over IP) apps have used for years. You can even get the same when making Skype calls. However, HD Voice has only transferred to mobile networks in the last year.

HD Voice closer to human speech

A normal, narrowband call, limits the frequencies to between 300 Hz and 3.4 kHz. HD Voice increases the upper limit to 7 kHz or higher – which more closely matches the frequencies used by normal human speech.

HD Voice also doubles the number of digital samples made from 8,000 per second to 16,000 per second.

The result is crystal clear speech quality and much less annoying background noise. The difference is immediately noticeable, it’s almost like having the person sitting in the same room as you.

This leads to much less scope for misunderstanding and broken conversations – it also reduces the need to speak loudly when talking on a mobile phone. The increased accuracy is likely to make life easier for people like me, a journalist, who conduct interviews over the phone.

What do you need for HD Voice?

Button says there are two components to using the HD service. First the network needs to be adapted to handle the service, but users also need suitably-equipped handsets. This means Vodafone customers calling other networks or other people not using HD Voice enabled handsets won’t get the higher call quality.

Vodafone lists HD Voice-ready handsets on the company's website (no longer online). Most of today’s most popular smartphones including the iPhone 5, Samsung S III (and IV), HTC One, Nokia Lumia 920 and Sony Xperia Z are all there.

One reason for introducing HD Voice is that a similar high quality voice technology is about to make its way into 4G LTE networks. Button says HD Voice is optimised for 3G networks, it means that phone users won’t find it jarring moving from the higher quality service on 4G phones when making calls on the 3G network.