Rory Cellan-Jones | 15:26 UK time, Monday, 25 January 2010

We're just getting used to the fact that our phones are turning into mini-computers able to do everything from scan a barcode to look at the Tower of London and tell us its history - anything it seems, but make a phone call. But here's a question - is the next killer app for mobiles going to be "voice"?

One thing that has hardly improved at all over the 25-year history of the mobile phone is the quality of voice calls. But now there's the possibility that we will soon see a radical improvement, one that make calls sound, in the words of one operator, "as if callers are actually in the same room". The technology that could provide that is called HD Voice.

This will use extra bandwidth on existing 3G networks to improve the quality of calls. In the UK , the Orange network is promising to introduce an HD Voice service later this year and other operators are also carrying out trials.

The problem is that new handsets will be required, so it'll take time for the "network effect" to kick in - both callers will need to be using HD Voice handsets, and both will have to be on networks that are HD-enabled. Of course, given the strains 3G networks are already experiencing as they cope with the flow of data from smartphones and mobile broadband dongles, it'll be interesting to see whether there is room for millions of high-definition voice calls as well.

But one reason I'm excited is the impact that this technology could have on the radio industry. I've written before about the challenge of doing live radio with quality audio. When broadcasting from home I use a 64K ISDN line for live radio rather than my fast broadband connection because it is far more reliable - the bandwidth may be limited but it's mine, all mine.

But if 3G handsets with HD Voice became commonplace - and delivered the promised quality - then radio reporters and interviewees could go live from anywhere with a decent network connection.

The other killer voice app that I'm hearing more about is one that's been around for quite a while. Voice recognition, used to control many aspects of your phone, isn't anything new, but it seems to be making giant leaps forward.

I've been testing both Google's voice search app and something called Vlingo on my phone over the weekend. A year ago, they seemed incapable of understanding a word I said - or indeed anything that was not said in a Californian accent.

But on Saturday I said "Financial Times palliative care" to both apps - and each time they came up with accurate results for this quite complicated search term, and sent me to the article I was seeking out.

I've also tried it as a way of searching out a map location, and that worked well too. Mind you, the Vlingo app, which claims it can also update your Facebook or Twitter status if you speak to it nicely, struggled with longer sentences. There is work to do, as we've seen, in getting a satisfactory result from automated voice recognition services.

What's clear, though, is that voice is about to become an important battleground again in the mobile world, and one where Google is eager to stake a claim. As well as Google Talk, which allows voice and video calls over the internet, since March last year it's been offering US customers Google Voice, giving them one number for all their phones, cheap overseas calls and voicemail on the web.

No word yet on when this service will come to Europe - but the mobile operators may not exactly welcome Google with open arms. After all, would you want a company with huge if hazy mobile ambitions and almost unlimited amounts of cash to come into a market where margins are looking increasingly tight?

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