On Wednesday there will be an emergency alert test on your phone

FEMA FAQ: No Telephone Interference Needs for National Wireless Emergency Alert System (NWEA) Tests During the First Quarter of the 2021 Census

According to a FAQ on the FEMA website, the test won’t interrupt a phone call. When it hits, it will be accompanied by a loud tone and a message that reads, “THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed.” The test will only be broadcast during a 30-minute window, so if you don’t want your phone to start blaring, turning it off should do the trick, according to FEMA:

FEMA is required by law to conduct national tests of the Integrated Public Alert & Warning System (IPAWS) at least once every three years. The last national test was in 2021.

You should only receive a message when the testing window is over. If an actual emergency happens that day, the test could be postponed — a backup test is scheduled for the following week.

If you know that you’ll be spending a lot of time listening to music while you wait for customer service, now is a good time to get that call.

The FEMA Emergency Alert System: A test to prepare for emergency communications, terrorist attacks, Terrorism, and other dangers to public safety

The Federal Communications Commission and the Federal Emergency Management Agency are in the midst of a test to prepare for emergencies. The aim of the test is to ensure the emergency messaging system is running smoothly in the event Americans are threatened by natural disasters, terrorism or other dangers to public safety.

Simultaneously, TVs and radios that are turned on and tuned to either over-the-air broadcasts or actively showing cable and satellite feeds will play a similar message to those shown on cell phones. FEMA writes that the Emergency Alert System is done in close partnership with state, local, tribal, and territorial authorities.

A big lift is required by the government, wireless carriers, cable and satellite providers, and local broadcasters. All of the major wireless carriers in the country will, during a 30-minute window, transmit the test to all of their subscribers’ phones that are within range of a cell tower and capable of receiving it.

FEMA has a page on its site that indicates CAP can be used for edge cases, like emergency phone networks, sirens, or digital road signs, and that some of these could be sent via computers, game consoles, search engines, and social media. An alert comes up when you watch a twitch stream.