All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is permissible to perform the Ruqyah whether or not one is sick, but what you mentioned is probably due to you raising your voice in front of the people, as this (problem) happens sometimes and then it discontinues by being accustomed to it. Indeed, this even happens to some preachers and Imaams when they first start preaching, and then it discontinues.
Hence, you should refrain from contemplating on this matter and you should be keen on calling the Athaan (call to the prayer) any time it is possible for you to do so.
The Prophet, sallallaahu ‘alayhi wa sallam, said: “If people knew the (reward) for Athaan and the first row, and they could not obtain them except by drawing lots, they would draw lots to obtain them.” [Al-Bukhari and Muslim]
Also, it was reported that the Prophet, sallallaahu ‘alayhi wa sallam, said to Abu Sa‘eed Al-Khudri: “I see that you are fond of sheep and the desert. So whenever you are with your sheep or in the desert and you want to call the Athaan for the prayer, raise your voice in doing so, for no human, jinn or thing hears the Mu’aththin's voice without being a witness to it on the Day of Resurrection.” Abu Sa‘eed added, “I heard this from the Messenger of Allaah, sallallaahu ‘alayhi wa sallam.” [Al-Bukhari and others]
Also, the Prophet, sallallaahu ‘alayhi wa sallam, said: “The Mu‘aththins have the longest necks of all people on the Day of Resurrection.” [Muslim and others]
Allaah Knows best.