What is the ruling on someone who intends to perform the Adhan at the time of prayer and performs it in his home or room, trying to intone it as he heard it in the Prophet's Mosque and Mecca?

Reciting the Adhan and repeating it at home, in a room, or any place, not for the purpose of announcing the entry of the prayer time or for prayer itself, is not legislated. This is because the Adhan was legislated for gathering and for prayer, unless it is for the purpose of training oneself and accustoming the voice to the Adhan. However, if the Adhan is for prayer and you are excused from attending the congregational prayer, it is sunnah for you to recite the Adhan and raise your voice with it.