Answer: There are five Sunnahs regarding the Adhan;

1. Reply to the Adhan by repeating the words of the Mu’addhin, except when replying to Hayya alas salaat and Hayya alal falaah, one should say La hawla wa la quwwata illa billahil aliyyil azeem

2. Recite Salawaat (Salutations Upon The Messenger Sallallahu Alaihi Wasallam) after the Adhan.

3. Read the Dua asking for al Wasila:

اللَّهُمَّ رَبَّ هذِهِ الدَّعوةِ التَّامَّةِ ، والصَّلاةِ الْقَائِمةِ، آت مُحَمَّداً الْوسِيلَةَ ، والْفَضَيِلَة، وابْعثْهُ مقَامًا محْمُوداً
الَّذي وعَدْتَ
“O Allah, Rabb of the perfect call and established Salaah, grant Muhammed صلى الله عليه وسلم Al Wasila and superiority, and raise him to the praiseworthy position which you promised him.” (Bukhari)

4. Then read this Dua;

أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ وَأَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ رَضِيتُ بِاللَّهِ رَبًّا وَبِمُحَمَّدٍ رَسُولًا وَبِالْإِسْلَامِ دِينًا
“I testify that there is none worthy of worship besides Allah, He is one and has no partner, and that Muhammed is His servant and Messenger, I am pleased with Allah as my Sustainer, Muhammed صلى الله عليه وسلم as a Messenger and Islam as my religion.” (Muslim)

5. Make any Dua between Adhan and Iqamah, as Duas are readily accepted at this time. [A Translation and Commentary of Riyad Al Salihin Vol2/Page 359]

And Allah Knows Best

Yusuf Moosagie