When the application of means for controlling sound at source
does not reduce the noise level in any space to that specified in paragraph 4.1.3, seafarers who are required to
enter such spaces shall be supplied with effective hearing protection
on an individual basis. The provision of hearing protectors shall
not be considered to be a substitute for effective noise control. Appendix 3 summarizes current noise abatement
methods which may be applied on new ships.