could you put up plasterboard or similar walls to segregate machines in the room into say 4 different areas?
once segregated from one another, what could further reduce the noise within the machine or guarding?
Speaking to the HSE with reference to a crusher we had that was over ideal noise levels, we introduced conveyor belting and a noise cabin with matting and seperated from the main machine to reduce noise and vibration.
Surely the manufacturers of the machines have specific ways of reducing the noise eminated from each, and newer designs and models will try to reduce the noise generated, would you be able to take insight from the newer designed machines and look to replicate some of the enhancements or replace old with new parts to reduce the noise per machine, at source.
In terms of noise, reflections of the noise can be reduced by foam or similar materials, so if you can get inserts say behind, under, and sides of the main areas, could it be lowered? if you have discussions with the guys working on the machines, they will be able to suggest areas where you could improve them, also showing that you care.
In addition, where there is noise, there is also vibration, so look for that too within your assessments of people.
if you had the ability to get a lower noise level, below requirements, then perhaps you could re-address the radio, however the HSE will say as low as reasonably practicable, i.e. reduce sources of noise in the first place. they will also suggest a monitoring regieme for occupational health so that there are some records in terms of the individuals affected.
Specsavers do independent noise assessments and you get the sheet if you pay them £10.00 when asking for an assessment.
On some sites it's really quite hard to find a low noise area to do the testing with occ health on site.
Links:
occ health buyer guide : http://www.hseni.gov.uk/purchasing_occupational_health_services.pdf
noise:
http://www.hse.gov.uk/noise/index.htm
with reference to education of people, they refer to the hearing video:
http://www.hse.gov.uk/noise/video/hearingvideo.htm
https://www.worksafebc.com/en/resources/health-safety/videos/the-hearing-video