Warning: That sound you may hear at 2:20 p.m. today is just a test

The Federal Emergency Management Agency is warning America that a nationwide test of two emergency signals will be conducted at 2:20 p.m. Wednesday and the loud noise could startle you. But don’t worry, these are just tests.

One test will be sent to consumer cell phones, but only for wireless customers who have opted into receiving Wireless Emergency Alerts. The second test, known as the Emergency Alert System, will be heard on televisions and radios. Both tests will begin at 2:20 p.m. EST.

This is only the sixth nationwide test of the EAS and the second for the WEA, though the first to just subscribers of the alerts.

“The purpose of the Aug. 11 test is to ensure that the EAS and WEA systems continue to be effective means of warning the public about emergencies, particularly those on the national level,” FEMA wrote in a press release. “Periodic testing of public alert and warning systems helps to assess the operational readiness of alerting infrastructure and to identify any needed technological and administrative improvements.”

FEMA’s efforts to modernize the nation’s public alert systems dates back to 2007.