Police siren shake-up

Cops’ new siren is a real shaker

If the flashing blue lights, sirens and blazing headlamps of a police car don’t manage to attract your attention, you could be in for a shock.

Auto Express Car Reviews

System emits low-frequency sound to warn of approaching 999 vehicle

Photos: NY Times/Eyevine

08th December 2007

The latest innovation to help emergency workers make their way through traffic is the Rumbler – a device that relies on the power of sound to shake the road up to 200 feet ahead of the vehicle.

Already in use by forces in the States, and designed by US company Federal Signal, the clever system comprises a pair of high-output sub-woofers and an amplifier.

Although it is no louder than a regular siren, the Rumbler emits low-frequency sounds which shake the ground, and the shockwaves are picked up by other road users. It’s designed for use in 10-second blasts in areas where it is safe for motorists to get out of the way, as long as they know what’s coming. The idea is that they ‘feel’ the emergency vehicle approaching, even if the audio system in their own car is turned up to full volume.