[EAS] New EAS handbook

[Botterell, Arthur@CalOES]

One of the reasons that EAS had to be ruled out as a transport for Earthquake Early Warnings was that extended attention signal.  Is there any remaining technical reason for the attention signal to continue for eight long seconds? 

>From a human-recognition perspective, the traditional two-tone has considerable weaknesses.  Because it doesn't vary in pitch or volume it can be hard to recognize as anything other than an unusually extended pause in programming.  Best practice nowadays is to include a frequency sweep that will be immune to either notches in individual humans' hearing or comb-filter effects in electronic.  E.g., Australia' s "Standard Emergency Warning Signal" (SEWS)... an audio sample is at: https://www.dfes.wa.gov.au/safetyinformation/fire/bushfire/BushfireMultimedia/sews.mp3.  Folks from Ohio may remember the semi-melodic Sohio winter weather sounder:
https://www.youtube.com/watch?v=MdunD-LOFTw.  Dynamic in both frequencies and amplitude, and very quickly recognizable even at low volume or under muffled listening conditions.

Seems like the extended drone of the two-tone may be one of the things listeners (and PDs) object to.  Certainly a sounder could be designed that could be recognized in a second or less.

Art