Telstra has confirmed that it will support high-definition voice calls on its HD Voice service as a feature of the iPhone 5, making it one of only 20 telcos to do so worldwide.
![](https://www.cnet.com/a/img/resize/d48d6b2d502713cc3b5341fbe3a4e00665ffec13/hub/2012/09/14/8acf3dd1-cc2e-11e2-9a4a-0291187b029a/apple-hdvoice_1.jpg?auto=webp&width=644)
(Credit: James Martin/CNET)
The ability to make and receive HD voice calls is one of the lesser-known features of the new iPhone 5, and, according to Apple, only 20 telcos worldwide will support the feature, including Telstra in Australia. Several of the US telcos can support HD Voice, but there is doubt as to which of the networks will offer it to iPhone customers.
Telstra first launched the HD Voice service on its network in June 2011. Since then, a number of handsets have supported the service, including numerous Nokia handsets, such as the N8; HTCs, including the current-generation One XL and Velocity; the Samsung Galaxy S2 and Galaxy S3; and the Google Galaxy Nexus. Telstra estimated that 70 per cent of its handset range in 2013 will be HD voice ready.
Also known as Wideband Audio, HD Voice is a technology that was first developed by Nokia, which extends the frequency range of audio transmitted from phone to phone. Many believe that it results in more “human”-sounding voices. The technology also greatly improves background noise suppression, so that call quality is clearer even in noisy environments.
One of the major limitations of HD Voice is that both handsets in the call need to be compatible with the technology for it to work. For a look at HD Voice in action, check out the Telstra-made information video below.