Dozens of loudspeakers are being installed around Melbourne’s CBD as part of a new emergency warning system, which police will test this month to give the public “a feel” for the sound of the alert.

Sixty-five speakers have already been installed at city sites where security cameras are in place, including Bourke Street Mall and Flinders Street Station.

Police Minister Lisa Neville said another 31 CCTV cameras would be installed over the next 12 months, along with the loudspeakers, to help keep people safe in a major emergency.

She said a test message would be transmitted over speakers at the State Library on December 28 to trial the system.

The message will include a warning signal and notify people it is a test only.

Traders in the area will be informed the test is happening.

The speakers operate like this:

• A police officer will read out a message to help direct people in the case of emergencies
• The message could be just in one location, or across the city
• The message will inform people to move to a certain location or take shelter in a building
• The loudspeakers will be used alongside other warnings such as text messages or warnings on social media

Ms Neville said the test message, just days before New Year’s Eve celebrations, would give people a idea of what the warning will sound like.

“It’s not about causing panic,” she said.

“It’s about making sure people have the information they need to manage a serious incident.”

Concrete planter boxes have been installed in Bourke St Mall to prevent vehicle attacks. Photo: ABC

Last month, a 20-year-old Werribee man was charged with terrorism offences after allegedly plotting to “shoot as many people as he could” at Federation Square on New Year’s Eve.

The Victorian Government has already announced it will spend $10 million to upgrade security in Melbourne’s CBD and introduce new counter-terror laws to detain younger suspects.

Temporary concrete bollards installed around the CBD are also being replaced with protective barriers, such as planter boxes, to protect against vehicle attacks.

Global counter-terrorism experts will be in Melbourne over the next three days as part of an international conference to discuss terrorism prevention.

It is the first time the conference has been held outside the United States.