I'm actually OK with is as long as it is voice only and not electronically amplified. Let is go as far as the wind will carry a non-amplified human voice.
Some of the more talented muezzins do not need a PA. In parts of the world where people have had a need to be eard over long distances they develop the ability. Many muezzins can be heard for blocks. Yodelers are famous in the world. In Viet Nam I was fascinated that many of the rural women could call and be heard over great distances without seeming to exert much effort. They don't yell, they just sort of squeeze their voice boxes down or something. Among the emigres here that generation seems to have died off but a few years ago one could hear it here.