No requirement save that all employers have an over riding duty to protect their employees from harm. If they fail to do so and employees are harmed, legal action can be successful and HSE may become involved.
Ford were criticised by the trades unions at Dagenham 20 years ago. The unions arranged for hundreds of workers to have audiograms and consultations with ENT consultants to build up a case that overall their hearing was worse than the normal population due to the noise on the factory floor. Given you are but one person, it might be worth seeking out how this action was resolved. Your employer might be interested.....