'Your attention please!' - QinetiQ makes rail platform announcements crisp and clear

The muffled sounds of rail platform announcements can be some of the most irritating and distracting noises around, especially when one is straining to hear important information.
Now QinetiQ has the solution as it launches its acoustic panel speaker technology for rail and subway networks at Innotrans 2004.

The technology, which uses existing platform fixtures and fittings to produce high quality sound reproduction for rail and subway public address systems, is currently being trialled on a number of rail and subway networks. It is hoped that a contract, and official adoption of the system, will be announced within the year.

Characteristic of so much of QinetiQ's success, the initial discovery of acoustic panel speaker technology came out of its military research. Fifteen years ago a well-known helicopter manufacturer came to QinetiQ to ask the company to help reduce cabin noise. Initial attempts were unsuccessful but an amazing discovery was made along the way: the panels surrounding the interior of the cabin vibrated vigorously and were excellent radiators of sound.

Professor Ken Heron, who led the initial research, came to the conclusion that while noise reduction in helicopter cabins might prove to be a longer term fix, the answer to creating bigger and better sound was at his fingertips.

'It was one of those Eureka moments. I discovered that the combination of light and stiff panels inside both rotary and fixed-wing aircraft were ideal mediums to radiate sound,' said Heron.

He immediately set to work on his own experiment, discovering that by attaching a moving coil actuator to, for example, aircraft panels, or trim panels as they are known, the entire unit was transformed into a single, giant speaker.

In 1994, the technology was exclusively licensed to NXT Plc, which built on the initial discovery with a series of additional inventions to create a technology that, today, can be applied to a range of commercial opportunities, including sound systems for business jets. NXT's Distributed Mode Loudspeakers, as they are known, offer enormous benefits in terms of sound quality, design flexibility and cost savings, for manufacturers across all market sectors.

In the aerospace arena for example, QinetiQ now has an exclusive licence to market the technology and has engaged with companies such as Lufthansa Technik (LHT), the cabin systems business and Maintenance Repair and Overhaul (MRO) arm of the Lufthansa Group. LHT has now installed QinetiQ's NXT acoustic panel systems on three business jets and there is an expectation that a major fleet order will be placed.

Speaking of the growing opportunities in the rail and subway businesses, John Davies, director Rail and Highways at QinetiQ, said: 'Acoustic panel speaker technology is a superb example of QinetiQ's spin-out technology and product development process. In the past there have been numerous examples of our technology being applied to solve complex problems for the military which have then successfully spun-out into the commercial arena. Acoustic panel speaker technology is yet another example of how discoveries made by QinetiQ for military research can be successfully applied to commercial applications.'

The advantages of flat panel speakers over conventional cone loudspeakers include a more even distribution of sound, broader operating bandwidth and the potential for overall weight reduction in a typical installation. Speech intelligibility is also noticeably improved.