I'm shocked that I haven't seen anyone point out that Vox can be forcibly silenced against his will and get fully muted, completely losing his voice.
(Ironic since his name means Voice lmfao)
BUT Alastor is unable to be silenced even when his mouth his foribly shut. He can still speak his mind and CANNOT be muted against his will. His voice literally cannot be silenced by others.
Not only is this yet another awesome foil between the two (which is the obvious)
But it also represents that radio is actually STILL most reliable long distance method of communication to this very day (in terms of its failure rate)
For instance, during extreme weather, weather radios are almost always the LAST thing that fails. Typically everything else will fail first. Cell towers can get knocked out easily, especially making phones useless. Power poles and powerlines easily can fail, and when the power goes out it renders most television and desktops useless, and you only have so much battery on your moblie devices.
BUT a weather radio will often STILL be working as normal even after all other methods of communication and warning have been lost. (Not always, but the failure rate during dire times is VERY low compared to literally everything else)