Johannesburg - The programme for any motorsport event carries a warning that 'Motorsport is dangerous - you are here at your own risk'. What they fail to mention is that motorsport is also very noisy.
Not as noisy as it was in the bad old days of Formula Atlantic, with highly-tuned Mazda rotary engines that regularly burned out video-camera microphones and officials' noise meters, but still loud enough, say doctors, for a day spent in the pits without ear protection to damage your hearing permanently.
Almost everybody who was working as pit crew for other competitors during the Formula Atlantic era - including me - now suffers from tinnitus (a ringing, buzzing or hissing sound in the ears) and some degree of hearing loss.
The upside is that the insane noise level put out by the rotaries led to the introduction of noise limits for racing cars.
The Motorsport South Africa handbook of 1999 limited racing cars and motorcycles to a noise level of 98 decibels at a distance of two metres with the engine running at 75 percent of maximum revs.
The current limit is 96dB for sports racing cars and single-seaters, and 93dB for tintops and road-based sports cars - although, as ATS communication consultant Adrian Burford pointed out in Burford's blog , some of the highly modified cars taking part in the recent Jaguar Simola Hillclimb sounded like they were way above those limits.
Anorak Alert!
A decibel (named after Alexander Graham Bell, the inventor of the telephone) is a unit of sound intensity - but it's based on a logarithmic scale, which means that for every 3dB increase, the noise level doubles.
Occupational safety researchers say you shouldn't be exposed to constant noise at more than 85dB for more than eight hours at a stretch - and for every three dB above that, the exposure time should be halved.
Normal conversation runs about 60dB, a pneumatic drill 15 metres away will hit you with 95dB and rock concerts run from a low of about 115 to a high of around 137dB.
Even a brief exposure to more than 145dB will cause some permanent hearing loss and just one blast at 165 or more will probably fry your eardrums for good; a really big backfire less than two metres away should do it.
Now consider the case of a race official such as Simola Hillclimb starter Marck Cooper, who was subjected to the full blast of each car - at least 96dB and in some cases noticeably more - as it left the line, for two full days.
Close to the action
Without some form of protection, just that one weekend would probably have caused measurable damage to Cooper's hearing, but fortunately for all the officials involved, Hearing Protection and Communication had provided the startline officials and the course marshals with 3M Peltor muffs, ranging from simple sound-damping earphones to active earmuffs that protect against explosive noises such as backfires - and for Cooper, a Formula One-style headset that allowed him to communicate easily with the chief timekeeper in his office above the start-line no matter who was revving up in front of him.
As a spectator, or even a pit crew, you don't need that level of equipment, but you owe it to your ears and, more particularly, those of your petrolhead-in-training offspring, to take along some ear protection next time you want to get close to the action at a motorsport event.
Even those little memory-foam pellets that you pop in your ears (get 'em at your local chemist for peanuts) will drop ambient sound intensity by about 20dB. For drag racing and drifting, a pair of industrial earmuffs would be better, and if your macho friends make sarcastic remarks, at least you won't be answering with: “Eh? What?”