Phones have sounded off across the country as part of a national emergency warning system trial on Monday — but some Australians say their devices remained silent and they did not get the message.

“TEST MESSAGE - AUSALERT. This is a Test of AusAlert, Australia’s new emergency warning system,” the message pinged to phones and devices said.

“NO ACTION IS REQUIRED.

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“In an actual emergency, follow the instructions in the alert to keep yourself and others safe.”

Monday’s critical alert test was sent to most phones, some smart watches and tablets.

While many said their phones were triggered, others said they did not receive an alert at 2pm AEST.

“I guess it’s just f*** me then. None of my devices went off,” one person said.

Another said: “Waited for the alert and nothing happened.”

A third asked: “Did anyone else not get (the) AusAlert on their phone?”

Hundreds of people reacted to a 7NEWS social media poll on Facebook asking whether they had received the alert.

By 2.30pm AEST, more than 1200 people had reacted that they had got the test

“Yes I sure did. It was really 10 seconds long. I had my volume up and still almost missed it,” said one.

About 280 said they had not.

“Nope, 3/4 of our phones didn’t,” said one Australian.

“Not on silent. The one that went off was on silent.”

Some pondered “how many kids got caught with their phones at school”, while others commented on fears from some sections of the community, saying “I’m now tuned to the 5G frequency I can feel it” and “didn’t turn into a zombie”.

Another described it as the “most anti-climactic thing ever”.

What do I do if I did not receive a test alert?

The AusAlert message system test allowed authorities to send emergency messages to compatible devices, as they will during disasters.

People who did not receive a test alert “don’t need to do anything”.

“It’s just a test. There are many reasons why you might not receive a test alert,” authorities said.

- Your device might be older or not support AusAlert, meaning it’s not compatible.

- Your device might not be updated to a software version that allows emergency alerts to be received.

- Your device might not have mobile signal at the time of the test.

- The mobile tower closest to you might not be working due to maintenance or outage, or it might not have any power.

- Your device might be switched off, in aeroplane mode or not connected to any mobile tower at the time of the test.

“This is all OK. 

“Finding out how devices behave is one of the reasons why we’re testing the AusAlert system before it launches.”

People who failed to receive an alert — and were near people that did — also “don’t need to do anything”.

“We expect devices to behave differently during the national test,” authorities said.

“You may get the alert at the exact test time, while someone you know receives it later or not at all.”

The AusAlert system will launch on October 1 and be managed by the National Emergency Management Agency.

- More to come . . .