The New York Police Department will outfit 5,000 patrol cars with Federal Signal's Rumbler vibration siren in the coming years, following successful testing of the equipment, reports the Wall Street Journal.
The NYPD has been running a pilot program with the Rumbler since 2009, and will add it to 500 vehicles by summer, according to Robert Martinez, NYPD's director of fleet service.
The Rumbler senses the primary siren tone signal and reduces the signal's frequency by 75 percent. It then amplifies the sound through two subwoofers, according to Federal Signal literature.
Federal Signal said the system's tone can sound for eight seconds and then automatically shuts off. The Rumbler can work with most 100/200-watt siren amplifiers, according to Federal Signal. The company provides vehicle-specific mounting hardware. Each Rumbler device costs $500.
Read the full story at WSJ.com.