There is no question on muting the alert. The sound, and sound levels are mandated. Here's the document that covers the look and sound of the alert message:
That is available in a pdf format as well.
From that document, section: Alerting Attention Signal comes the following:
Wherever possible, the Canadian Alerting Attention Signal should be used to introduce audience alert messages that are identified “Broadcast Immediately” and distributed audibly.
In the event that LMD (Last Mile Distributor) equipment cannot insert the Canadian Alerting Attention Signal, the use of an alternative alert signal or tone available to the LMD should be used.
Composition: The Canadian Alerting Attention Signal is comprised of two alternating complex tones. Tone 1 is formed by the combination of three frequencies, 932.33 Hz, 1046.5 Hz and 3135.96 Hz, modulated at 7271.96 Hz. Tone 2 is formed by the combination of the three frequencies 440Hz, 659.26 Hz and 3135.96 Hz, modulated at 1099.26 Hz.
Relative volume of Canadian Alerting Attention Signal: Should be normalized to stations output.........
LMD (Last Mile Distributor) program audio should be off when the Alerting Attention Signal is played.
So, if anyone has strong objections to how the alert sounds and looks, then they should press for amendments to the following document:
National Public Alerting System
Common Look and Feel Guidance 1.1
I had to scramble to turn the tv off because the volume of the alert was so loud, it was like a smoke alarm and my dog panicked. I still have a noise hangover two hours later. I believe the alert will cause hearing loss. How absurd and counter-productive.
Nerve damage is permanent. I don't have great hearing as it is. When I played in rock bands I would wake up the next morning with ringing in my ears, and that's how I feel now.