I don't know if this can expand to cover every country, but we could add some with English language broadcasts (and French as well for CA).
These links have some description as well as example audio/video:
https://crtc.gc.ca/eng/television/services/alert.htm
https://en.wikipedia.org/wiki/Alert_Ready
https://emergencyalertsystem.fandom.com/wiki/AlertReady_(Canada)
I don't know if this can expand to cover every country, but we could add some with English language broadcasts (and French as well for CA).
These links have some description as well as example audio/video:
https://crtc.gc.ca/eng/television/services/alert.htm
https://en.wikipedia.org/wiki/Alert_Ready
https://emergencyalertsystem.fandom.com/wiki/AlertReady_(Canada)