On a related note, I think radio commercials with sirens and honking horns should not be allowed. I have been confused by these a number of times and it is a real nuisance.
Try this at home (and only at home), on a signal generator:
EAS combined tone (TV) 853 Hz sine-wave + 960 Hz sine-wave ("+" means simply combine both waves together, neither modulation nor any other fancy convolutions)