It was narrated from Ibn 'Umar that:The Messenger of Allah said: "Whoever calls the Adhan for twelve years, he will be guaranteed Paradise, and for each day sixty Hasanat (good deeds) will be recorded for him by virtue of his Adhan, and thirty Hasanat by virtue of his Iqamah
Hadith No. 728
Sunan Ibn Majah
Gradings:
Al-Albani:
Sahih
Muhammad Fouad Abd al-Baqi:
Sahih
Shuaib Al Arnaut:
Daif
Zubair Ali Zai:
Daif