[paradox460]

Now that you mention it, I do remember hearing the spoken message every Tuesday.

Still, a big loudspeaker is even simpler than a classical motorized siren. No moving parts!

[gojomo]

Yep! And as of the shutdown over 4 years ago, even if their control plane was insecure, they presumably had 119 working loudspeakers of the proper loudness/weatherproofing/etc.