Sony has signed an agreement with Dublin Institute of Technology's Audio Research Group to license a software tool for PlayStation's Singstar game.

ADRess - azimuth discrimination and resynthesis - is essentially a sound-source separation tool which will remove the original vocal from the karaoke game without compromising the quality of the audio.

While there is similar software available elsewhere, the DIT's research group's technology has proved it is capable of keeping the integrity of the original recording intact while removing the vocal track.

"Sony approached us because it was looking for something that could mute the original vocal on the game so the user was just hearing the remaining backing track," said Dan Barry, head of the Audio Research Group at the Dublin Institute of Technology in Kevin Street.

Dr Barry said: "It was only interested if the quality of the other instrumental tracks was maintained because, although there are a lot of rough-cut vocal removers, they usually leave the audio content in ribbons."

Interestingly, the research group had to refine and invert its methodology because Sony wanted to get rid of a source as opposed to isolating and separating it.

After initially taking out a trial licence, Sony Computer Entertainment Europe took a full licence agreement once it successfully ported the technology to the game.

According to Sony, it did have the vocal-free feature on the first Singstar release but it was achieved by having both an instrumental track and an acapella of each song.

Sometimes record labels could supply these and other times they had to supply the original recorded multi-tracks, which then had to re-engineer from scratch, with each song taking three to six weeks to prepare and sign off for the game.

Sony said the DIT group's technology was innovative.

It had been searching for this type of software since the first version of Singstar but, until Dr Barry's team came along, it had not found anything that could deliver the quality it was looking for.

Niall O'Hanrahan, managing director of Sony Computer Entertainment Ireland, said licensing this piece of software had enabled Sony to produce an improved product which it feels offers the consumer a higher-quality gaming experience.

"It is important to acknowledge and promote the high standard of research available from Irish third-level institutions, and we hope to work with DIT again in the near future," he said.