Sadly we have to group together in order to convince Heath and Safety and bean counters that this issue must be resolved.
Passenger do not sit in an area that if full of sharp obstructions they have a relatively cushioned environment compared with the cockpit and do not spend 800hrs per year in the noise levels we suffer.
Just wearing a cap over your head you will hear the noise levels reduce, with regard to a source backing this information, it is just what I have read on PPRUNE and discussed with other pilots.