TOOL FOCUS: Dolby Axon

TOOL FOCUS: Dolby Axon

By Develop

January 13th 2009 at 12:18PM

Dolbyâ??s involvement in videogames has come a long way since King Arthurâ??s World on the SNES back in 1994, the first game to feature Dolby Surround.

Price: Available on request
Company: Dolby
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Ever since that 1994 debut, they’ve continued leveraging their considerable expertise and rich heritage in high quality audio within the games business. The latest Dolby offering is Dolby Axon, a scalable integrated voice-chat solution with which they aim to raise the bar for virtual world voice comms, allowing thousands of players to communicate via sophisticated new server software.

Online gaming has become a huge phenomenon over the last decade or so with voice-chat a vital part of the multiplayer experience. Many gamer headsets have been mono – one ear-piece and a microphone – potentially leading to a loss of immersion. You can’t fully hear sound from the right side because your ear’s blocked by an ear-piece. However, the latest headsets from companies such as Astro Gaming, Plantronics, Triton and Turtle Beach all feature Dolby Headphone technology. It seems there’s a growing appreciation of the desirability of integrating the voice-chat experience with a full surround soundscape.

“The natural extension for us has been to address the issue of how, even with such systems, voice itself can still break that immersion by not being panned in surround,” says Matt Tullis, senior manager of Dolby’s game division. “There’s a disconnect when someone’s shooting at you from over there someplace but they speak right inside your ear in mono. We felt there was definite room for improvement. Add to that the fact that many voice codecs are low quality due to bandwidth limitations, and we thought ‘Hey, Dolby can help!’”

Enter Dolby Axon – a technology created from the ground up for games – by a development team which also happens to be a gaggle of online gamers.

Tullis continues: “Firstly, with Dolby Axon we can surround-pan voices associating them with game avatars in a believable way. We can take occlusions into account so if someone goes behind a wall, you’ll no longer hear them. And we have distance attenuation – if someone moves away from you, their voice gets quieter. This really contributes to re-achieving that immersion – it puts you in the game.

“To improve audio quality we’ve integrated some useful processing to address the inherent problems of voice-chat: clipping detection and limiting to alleviate the problem of inferior microphones, for example. Another problem you get is that people end up having their microphone volume set up really loud, while others have a really quiet setting, especially on the PC side of things where you have more control over volume input. As a player you adjust your volume for what you think is normal only to find someone else blows your ears off with a really hot signal, which is why we have dialogue levelling,” he says.

“We evaluate the incoming voice levels and balance them roughly to facilitate a more consistent experience. If that’s not enough we also have noise reduction and echo reduction for those situations when maybe you’re playing on a home theatre system with your speakers cranked up and you’re really excited – trouble is that audio can feed back into the microphone. All of a sudden, you hear echo and it undermines the experience because you’re hearing these sounds from someone else – and it makes it harder to speak to other people. Our echo reduction works really well allowing you to pump up the volume and not worry about affecting everybody else.”

The team has also worked hard to design its own special codec for Axon. “It gives us some pretty high quality voice at low bandwidth,” adds Tullis. “We can do a full surround sound scene with as low as an average of 16 kilobits per second
per player.”

Dolby Axon also offers the prospect of compelling game-play opportunities – for instance, you could place a ‘spy’ microphone and listen in on your opponents or attach a voice to an object, say a mine – using voice to lure another player astray. It also features ‘voice fonts’ for players that want to role-play gender-bending. Other manipulations to represent fantasy characters are also in the pipeline. If you play the part of an elf, you may be able to sound like one.

Although Dolby’s focus has been on PC, Tullis says there’s no reason the technology couldn’t run on consoles. There is no news regarding a business model as yet, though clearly there will be a licensing aspect. Tullis adds: “We’re just focusing on getting the SDK out there whilst collaborating with our valued developer partners to establish the best option on bringing this to market.”

www.dolby.com