Sayyiduna Abu Juhaifah (may Allah be pleased with him) says: I saw Sayyiduna Bilal (may Allah be pleased with him) giving the adhan, that he would turn (while saying "Hayya 'ala-s-Salah" and "Hayya 'ala-l-Falah") and I was watching his mouth turning this way and that. In another narration, it is further stated: that he was turning to the right and left and had both his fingers in his ears.