1. It is desirable that the background noise levels at listening posts should not on
average exceed the noise level defined by octave-band levels as follows:
2. Ship designers and builders should be encouraged to meet this requirement
in new vessels. Measurements should be made when possible in accordance with the method
recommended above, in order to check results.
3. So far as existing vessels are concerned, it is recognized that problems
of a ship construction nature may make it difficult, if not impossible, to meet the
requirement. These vessels should therefore comply as far as is feasable.
4. On the basis of information received from Administrations concerning noise
levels measured on existing vessels, IMCO will give further consideration to the
possibility of making a Recommendation on maximum permissible noise levels at listening
posts