It should be first stressed that the adhan (call to Prayer) symbolizes the presence of Islam throughout the world. To have the same language for the adhan and Prayer for all people of all nations, races, and tongues is such a powerful connecting force that bonds all the Muslims of the entire world into a single Ummah and a universal brotherhood. Wherever you go in the world, the moment you hear the call of the adhan you will feel that in this place there is someone or some people who belong to the Muslim community and now he is calling for Muslim Prayer. You may go to London, Nigeria, or Indonesia for Prayer, but you will hear the same familiar call everywhere.
There is a consensus and a tradition of 15 centuries that it should be recited in its original language. Since the main aim of the adhan is to remind Muslims that it is Prayer time, the adhan has to be recited in its original language in order to reach all Muslims who speak various tongues.
In his answer to the question on translating the adhan, the prominent Muslim scholar Sheikh Muhammad Iqbal Nadvi, Imam of Calgary Mosque, Alberta, Canada, and Former Professor at King Saud University, Riyad, Saudi Arabia, states:
“This question is new but it sounds interesting. The way I see this question consists of two things:
1. The first case is if by “translating the adhan into the local language” you mean after doing the Arabic one in the microphone or speaker and to use it as a standard version of the adhan to be done regularly all the time. Of course, this is not allowed. The reason why it is not allowed is that the adhan is considered as sha`irah in Islam. Sha`irah is a ritual that we have to keep as it is and perform it the way we are taught in religion. For example, in Prayer, there is a difference between saying “Allahu Akbar” and saying “Allah is Greatest”. The first one is sha`irah while the second one is just a translation. So, if you mean by your question that you make a different adhan in your local language, then it is not allowed on account of the reason I mentioned.
2. The second case is when you want to inform your people about the meaning of the adhan by translating its meaning in many ways like typing it in fliers or telling the people about the meaning. There is nothing wrong in doing so, but on the condition that you don’t make it all the time after the Arabic adhan. The purpose again is to keep the sha`irah as it is.”