text: Azan's original purpose is to let Muslims know that it's pray time.\nLogic says that it can be replaced with any other means, but it has some spiritual value in the hearts of Muslims, so it is still heard till now. It became problem when voices became bad and it isnt an issue whether the Moazen (the man who says the Azan) has bad voice or not. also, too many megaphones ( i m talking about Islamic countries) are calling at the same time in a small area making a big noise because of interference.\ntemples or churches uses indoor loudspeakers, i think.