Musnad Abu Ya'la al-Mawsili 245:35

Abdullah ibn Abd al-Samad narrated to us, al-Qasim ibn al-Hakam narrated to us, from Sufyan, from Talhah ibn Yahya, from Isa ibn Talhah, from Mu'awiyah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The people with the longest necks on the Day of Resurrection will be the callers to prayer (mu'adhdhins)."