If they're trying to make that warning sound more effective they should use the sound of someone screaming because humans are evolved to be most sensitive to that sound, plus it's as natural as it gets!,(reply>), @bilibiliism, there was a lorry which used to deliver something to my secondary school which said "This vehicle is reversing. This vehicle is reversing." Once it stopped reversing after "This vehicle is" and sounded very philosophical.,(reply>), Then you'd wonder why there are 3 same voices screaming and call 911. You'd also feel bad for the voice actor, imagine him/her actually screaming and needing for help, but one bats an eye because they think it was just some truck.,(reply>), Kill3rCat Good one!,(reply>), Use the Wilhelm scream,(reply>), Nope nope nope