Due to their occupational (in a manner of speaking) hazard, they have been forcing their voices to serve others and one day, someday, their once precious voice seized on them "unexpectedly and out of the blue", as they all thought. Does it happen "out of the blue" in a real sense? Not really.
Some of them admit that they had lost their voices before... and numerous of times, but always (at least to a reasonable degree) gained it back. Then it came the time that they pushed it "the very last time" and now, as a result, their voices had been drawn to a very low position... almost to the point of no return. At this point, nevertheless, they had finally begun their search for professional help.
What kind of help you would think they had been searching for? You would never guess. They were trying to perfect themselves, i.e. they had even begun doing yoga, staying upside down on their heads, eating raw fruits, exercising "like mad", employing all alternative natural and homeopathic remedies and looking and feeling like a million bucks, except the voice was still not working... How so, you may ask?
This is my answer:
Let's imagine that the Mercedes that I have been driving , would no longer be able to take me places and it would stall every time I try to turn the key to start it. Should I wash it, make it shine and work on its body so it would look good and pristine...? Or should I rather look into its mechanics and define what exactly is not intact? The most probable issue would be with the mechanics defaulting inside of that wonderful, shiny Mercedes... And until I correctly assemble all the internal parts in that Mercedes, it will remain to be shiny and beautiful.., but, unfortunately, it will never take me places.
Similarly, instead of (or along with) perfecting their physical bodies and all other organs associated with it (however not, in real sense, related to voice/vocal mechanics), these people should look a little closer to the cause of their voice loss and identify it accordingly.
The fact is that these people had been brutally misusing their voices throughout a prolonged period of time, not realizing that their vocal cords are not "made from steel", so to speak. Some of them had finally "clued in" after feeling great and looking good, that there is perhaps something else they would need to be doing to actually fix their voices. And now finally came the time when their wounded voices needed to be restructured to a different set of muscles (their facial muscles) and then put to work in conjunction and coordination with their abdominal muscles to minimize and practically eliminate the use of their throat, larynx and vocal cords.
Once the pressure of the sound had been removed from the vocal box, the whole vocal anatomy had to be treated with natural herbs and remedies; and sometimes even with homeopathic remedies, if (and/or when) needed.
The individual's voice health had been addressed and the whole modality of the proper "vocal behaviour" finally had been changed and employed.