Last year, I was in Montreal just before the Canadian F1 Grand Prix. Chatting to fellow acousticians over a beer one evening, I was surprised to be told that they were taking ear plugs and muffs along to the race to protect their hearing. Up until then, I never realised how loud formula 1 cars were. At the Montreal race, acoustic engineer Craig Dolder took measurements, reporting peak levels of almost 140 dB; this is above the pain threshold .
For the 2014 season, the engines in the F1 cars have been radically changed. The piercing scream from the old V8 engine has been replaced by the more dulcet tones of the 1.6-litre V6 turbo. There have been complaints about the quietness of the new engines, and headlines like ‘Bernie Ecclestone admits to being ‘horrified’ by quiet engines on new F1 cars’ 
According to the sport’s governing body FIA, the sound pressure level for the new cars is 11 decibels lower than before (134 dB compared to 145 dB).  Normally in acoustics, a rule of thumb is that a 10 decibel change sounds likes a halving of loudness. Although, both new and old engines produce noise levels likely to produce pain in the ear.
This YouTube video gives a great comparison (although the 2013 recording suffers from the recording device being overloaded):
The difference in the cars isn’t just about the absolute sound pressure level, there is also a big difference in the sound quality. The old scream has been replaced by a car sound that reminds me of a superhero’s car from a movie. The old V8 produced sound particularly in the frequency range 500 – 2500 Hz, this is the range where our hearing is particularly sensitive and at the top end is where human screams sound. The new engines are producing their energy about an octave lower, away from the range where the ear is most sensitive, and at a frequency lower than human screaming. No wonder fans have complained of a less visceral feeling.
Below are spectra comparing two onboard recordings of 2013 and 2014 cars.
One interesting thing to note in the YouTube video, is that in 2014 the spectators seemed to have dispensed with hearing defenders. If that is the case, the sound level reaching their ears would be greater with these new quieter cars. If I was an F1 fan, I’d much rather listen to the new cars, and be able to dispense with the hearing protection.
Photo: Nic Redhead from Birmingham, UK