Reference: Sharh ‘Umdatil-Fiqh – Tape No.8, Question No.14
Question: Whoever says that [using] the microphone suffices [the mu.adhdhin] from turning [the heard a little to the right and left] during the adhaan; is his opinion correct?
Response: No [it is not correct]; turning [the head a little to the right and left during the adhaan] is a Sunnah which is not to be abandoned. [So the mu.adhdhin] turns [his head a little to the right and left during the adhaan] even if he has a microphone, doing so in accordance with the Sunnah.