The Sydney CBD Emergency Warning System will be tested at 12.15pm on Friday.



There are 98 speakers located throughout the city centre, with 13 variable messaging signs positioned at transport hubs in the city.

The test will be carried out at selected sites across the central business district.

Police reminded members of the public they should not be concerned.



"Those who reside, work or travel through the Sydney CBD need to be aware of the warning system, what it sounds like and what it is used for," police said.



The system is tested monthly to remind the public the warning system exists, and to make sure it works.