It is recommended for the muezzin to place his fingers in his ears during the call to prayer: by placing his fingers in the ear canal; his call to prayer without it is good, and with it, it is better. Ibn Abi Juhaifa, may Allah be pleased with him, said: 'I saw Bilal calling to prayer and turning, following his mouth here and there, and his fingers in his ears,' in Sunan al-Tirmidhi 1: 375, and he said: Hasan Sahih, and in al-Mustadrak 1: 318, and Musannaf Abdul Razzaq 1: 467, and Musnad Ahmad 4: 308, and al-Mu'jam al-Kabir 22: 101. And from Sa'd al-Qaradh, may Allah be pleased with him: 'The Messenger of Allah, peace be upon him, ordered Bilal to put his finger in his ear, and said: It raises your voice,' in al-Mustadrak 3: 703. See: al-Durr al-Mukhtar 1: 260, and al-Wiqayah p.140.