I generally do not hear loud vehicles directly next to me while driving down the road. Not cars or motorcycles. My own radio, tire noise, and engine noise is enough to drown out all but the absolute loudest, except maybe when I'm going very slow.
However, I don’t like the idea of automatically ticketing people with technology devices alone despite the obnoxiously loud noise pollution from these vehicles. Police can easily hear these vehicles and pull them over for a violation.
In practice this doesn’t happen, however, at least here in the UK.
Police are not issued with equipment to measure noise levels, and on a busy road it can be difficult to identify (provably and conclusively) which vehicles are making the noise.
Which is exactly why technology like these “noise cameras” are needed!
Especially in the nice areas of London you could probably drive for years without numberplates and nobody would ever stop you.
I've even seen the police crack out light meters to fine boy racers with overly tinted windows.
Edit: If I'm able to hear them, it's immediately after they have passed me.