| Last updated 9:50 AM, May 25 2021 GMT+1 Some people in East Suffolk might hear an unusual and loud alert coming from their phone today (25 May). That's because a test is being performed on a national alert system the government wants to put in place in case of a serious emergency. In real terms, what it will mean today is that random phones are going to make an unexpectedly loud noise. If it happens to you, at least you'll know what it was, and can get on with your day. Advert 10 However, if you hear it again at some point in the future, it might be worth checking your phone to see what's going on.