How to call out the azaan:

اَللهُ أَكْبَرْ اللهُ أَكْبَرْ

Allah is the greatest. Allah is the greatest.

اَللهُ أَكْبَرْ اَللهُ أَكْبَرْ

Allah is the greatest. Allah is the greatest.

Note: The letter ر (raa) in the first أكبر (akbar) can be read with a sukoon without joining it to the word ألله (Allah), or with a fathah by joining it to the word الله (Allah). To read it in any other way will be against the Sunnah.