Clearing the way for audible announcements

Muffled or completely inaudible passenger announcements made by aircraft pilots and train drivers could soon be a thing of the past.

Research specialist Qinetiq is in discussions with aircraft manufacturers, including Airbus and Boeing, and rail industry tier-one suppliers about equipping vehicles with flat-panel speakers to improve the quality and clarity of music and announcements.

Flat-panel speakers are based on an electromagnetic exciter, which is attached to aircraft trim panels or the interior panels of trains, causing them to vibrate and generate noise. The speakers provide a more even distribution of sound, broader operating bandwidth and – particularly in aircraft – potential weight savings compared to conventional cone speakers, said Robert Coppard, business group manager for structural design at Qinetiq.

The technology, which was invented following military research into helicopter cabin noise 15 years ago, was licenced to NXT in 1994. But Qinetiq now has an exclusive licence to market it to the aerospace and rail industries. ‘We have an interest in rail, and we are looking at applications in which voice and speech intelligibility is important, where you can’t hear or understand the announcements. We are already talking to customers,’ he said.

Installing the speakers on trains is more complicated than aircraft, as less of the existing equipment can be used, including PA systems and interior panels, while space behind panels is also limited. As a result the company is far more advanced in marketing the technology to the aerospace industry, and the speakers have already been installed on three business jets through its work with Lufthansa Technik.

Coppard claimed 100 more aircraft could be equipped with the technology over the next 12 months. ‘It is going to go on to most production aircraft as it isn’t complex (to install) and the benefits are so great. I could see this becoming a generic,’ he said.

Following feedback from aircraft manufacturers the company is carrying out further development work involving fitting the devices to ceiling rather than wall panels, so seats do not have to be removed if the speakers require maintenance or replacement.

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