There are seven Mustahabbs in Adhaan:
a) to stand facing Qiblah,
b) Not tohasten in saying Adhaan,
c) To put both index fingers in the ears,
d) To call the Adhaan from a high place,
e) To say the Adhaan in a loud voice,
f) To turn the face towards the right at ‘Hayya alas salaat’ and towards the left at ‘Hayya alal falaah’,
g) To say ‘Assalaatu khayrun mina nawm’ twice after ‘Hayya alal falaah’ in the Adhaan of Fajr.
Saying Adhaan without Wudhu is permissible but it is disliked.
In a Hadith, Nabi :saws: told Bilaal (RadhiallaahuAnhu), ‘Place your fingers in your ears for verily it raises the voice more.‘ The listeners should respond by repeating the exact words of the Muazzin, however, after ‘Hayya alal Falaah’ and ‘hayya alas salaat’, he should respond by saying ‘Laa hawla walaa quwwata illaa billaahil aliyyil adheem’. In Fajr Adhaan after hearing, ‘Assalaatu khayrun minan nawm’, one should say, ‘Saddaqta wa bararta’. In the Iqaamat, after hearing, ‘Qad qaamatis salaat’, one should say, ‘Aqaamahallaah wa adaamahaa’. It is not necessary for the person who is calling out the Adhaan to respond as well.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai