The Code on noise levels on board ships has been developed to provide international standards for protection against noise under the provisions of regulation II-1/3-12 of the SOLAS Convention. The Code, adopted by resolution MSC.337(91), recognizes the need to establish mandatory noise level limits for machinery spaces, control rooms, workshops, accommodation and other spaces on board ships, and enters into force on 1 July 2014.

The Code applies to new ships of a gross tonnage of 1,600 and above. The specific provisions relating to potentially hazardous noise levels, mitigation and personal protective gear contained in the Code may be applied to existing ships of a gross tonnage of 1,600 and above, as far as reasonable and practical, to the satisfaction of the Administration. The Code may be applied to new ships of a gross tonnage of less than 1,600 as far as reasonable and practical, to the satisfaction of the Administration.

The Code includes:

- a format for noise survey reports;
- guidance on the inclusion of noise issues in safety management systems;
- suggested methods of attenuating noise; and
- a simplified procedure for determining noise exposure.
These regulations, recommendations and advice are intended to provide Administrations with the tools to promote "hearing saving" environments on board ships. Although legally treated as a mandatory instrument under the SOLAS Convention, certain provisions of the Code remain recommendatory or informative.