The noise about Speedway sound had me wondering how loud is Formula One?
There is nothing like the sound of a pack of F1 cars at full throttle. Its one aspect that TV can not convey even if you have the best home theatre. Engines spinning at 18-19,000 rpm don't sound much like normal cars, even race cars, but more like the sound of metal being shredded. That is probably whats happening!
I found an article about Jordan (below) that states Formula One engines create levels of about 130 decibels or 10,000 times normal conversation. Makes those 91 decibel speedway cars seem tame!
Link: Lucent's Bell Labs & Jordan Grand Prix communcation.
"A Formula One cockpit is one of the noisiest places in the world, but even in this extreme environment, drivers must maintain a vital link with their pit crews," said Michael T. Frank, a developer within Lucent's Microelectronics Group. "In addition to the roar of an 800-horsepower engine that sits directly behind the driver, the cockpit is subjected to high levels of vibration, extreme temperatures and moisture." Engine noise is 10,000 times the level of normal conversation, reaching as high as 130 decibels. By comparison, a person standing about 100 metres from a jet plane would be exposed to 120 decibels. A foghorn produces 105 decibels and a helicopter hovering about 150 metres overhead generates about100 decibels. Such external noises can drown out the driver's voice at critical times during a race, meaning the driver can only communicate at lower engine revs.