Researchers at Canada's University of Windsor Sound Quality lab are using the Brüel & Kjær NVH Driving Simulator to determine whether a new type of police siren will better alert drivers to approaching police vehicles and save lives in the process.
The new siren is called a Rumbler and emits a low-frequency modulating sound in addition to the conventional high-frequency wailing siren. “Modern automobiles are much better designed to isolate the interior of the vehicle from exterior sounds such as roadway noise. Unfortunately this also results in drivers having a more difficult time to hear high-frequency emergency sirens which are relatively easily attenuated by these sound packages,” said Professor Colin Novak from the university’s Noise, Vibration and Harshness Sound Quality Research Group. “The low-frequency modulation produced by the Rumbler is better able to penetrate into the car. But what we really need to determine is how much does it grab the attention of a driver and does it do so without startling them.”
The Windsor Police donated a Ford Crown Victoria cruiser fully outfitted with all the lights and sirens to the school’s Mechanical and Automotive Engineering department to facilitate the research. “The Windsor Police lost nine cars last year alone in accidents this past year,” said Novak. “If we can show that the siren, that costs about $700, is a more effective attention grabber, it will be money well spent. This is especially true if it saves just one life”.
Key Tool to Help Save Lives
Once the noise data has been collected from the installed Rumbler in the cruiser, the research team will use the Brüel & Kjær NVH Driving Simulator to determine a driver’s reaction to the siren. The simulator is just like driving a car, complete with a steering wheel, foot pedals and three very large screens which project the roadway in front of the driver, including roadway signs and other traffic. While listening through headphones, the driver is able to hear a very realistic representation of the car’s sounds, and in this case, also the approaching police car.
“Using this technology, we are able to gauge the effectiveness of the Rumbler compared to other more conventional emergency sirens,” said Professor Novak. “This really is an innovative use of this very powerful engineering tool “. Presently the research group is also using the simulator to study hybrid vehicle noise.
The project will take approximately six months to complete with participants in the study taken from the student and general population.