It's a police siren that cannot be ignored.
Officers in Oklahoma are excited over a new piece of equipment called the "Rumbler," which is a very loud siren.
It is so noisy, in fact, that drivers will be able to feel their seats vibrate from the sound.
Tulsa policemen say even with their lights on and sirens blaring, most drivers don't notice their patrol cars.
But the low tone surprises many drivers, making them look up and pull over.
"I like it," said Tulsa Police Officer Harold Goad.
"I used it this morning and yesterday and in one or two cases it was obvious the rumbler brought the attention to the driver."
Some in the community debate if the Rumbler could pose a health risk.
Area doctors report they didn't know enough about the Rumbler to make a comment, but Tulsa Police say it's like any high tech sound system where the woofer and amplifier make you feel a slight tremor in your body.