Is it considered a sin not to listen attentively to the Adhan and repeat after it, especially when the Muezzin says in the Fajr Adhan, "Prayer is better than sleep"?

Responding to the Caller to Prayer (Mu'adhdhin) is supererogatory according to the more preponderant opinion, and there is no sin in omitting it. Some scholars, however, have gone to the extent of deeming it obligatory. One should interrupt conversation to repeat after the Adhan, and not feel shy about doing so; rather, one should hasten to it and teach it to others. When the Mu'adhdhin says: "Prayer is better than sleep" in the Fajr Adhan, one should respond with: "Prayer is better than sleep," or "You have spoken the truth and acted righteously," according to some scholars.