HD audio in phone calls and web chats is on the way

Nerd Insider By Nerd Insider, 12th Oct 2012 | Follow this author | RSS Feed | Short URL http://nut.bz/3mezohcf/
Posted in Wikinut>News>Technology

A post about the iPhone 5's wideband audio calling and the new Opus codec which will be used in Skype. Both have been designed to give significantly better audio quality.


I've never really given it much thought until recently, but why do our voices sound strange over the phone and on webcam chats? (and especially when we hear our own played back). Sure, you can recognise someone's voice quite easily but, it does always sound like a pale imitation of the real thing, and that's because it is.
Part of the reason is down to the microphones and speakers used, but that's not the whole story.

The frequency of the human voice varies between 80Hz and 14,000Hz, which is actually a seriously wide range of frequency. However, the majority of phone providers limit the range of frequency they carry to around the region of 300 to 3,400Hz. Effectively they're chopping away the lowest and highest tones in our voices, and this goes a large way to explaining why our voices sound a little strange on phone calls. The same goes for the audio codecs which carry our voices when we use webcam chat or VoIP.

It looks like that's all about to start changing with the introduction of iPhone 5 wideband audio and Skype's Opus codec.

iPhone 5 Wideband Audio

The new iPhone has been designed to include the AMR-WB HD voice codec. However, there is some serious scepticism about whether this will become popular or not. First off, for it to be of any use both parties need to be using a phone which supports it. Secondly, the mobile networks need to be capable of supporting the codec. At the moment it doesn't look like any of the major US mobile networks are going to support the codec.


Skype have also been working to improve the quality of the audio on their calls. To this end they've been heavily involved in developing the new open source Opus codec. This new codec is designed to be very adaptable, especially when dealing with varying internet connection speeds.

However it's the HD audio capabilities which will bring one of the most noticeable differences. If both users have sufficient bandwidth the new codec will allow a CD quality, fullband stereo audio experience.

Interestingly Skype have said they hope Opus will bring "…consistent audio quality to all our users on every device". If implemented in the iPhone it would mean you could use the Skype app to make an iPhone video call with HD audio (obviously you could also make Skype VoIP call with HD audio).

The new Opus codec looks set to become very popular. The Internet Engineering Task Force (IETF) has recently accepted it as a new web standard. Also the development has involved some of the internet's biggest hitters including Google, Microsoft and Mozilla. On top of all that it's free for developers and the public to use.

Have you tried wideband audio calling on the iPhone 5 or tested the Opus codec? If so we'd love to hear what you thought of them.

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