Adhan without the Imam's permission

A: It is permissible for him to do so, as he is the one responsible for the Adhan. It is also permissible as long as he knows the due time (of prayer) whether he recognizes it himself or is informed by others, and whether the Imam is present or not. Moreover, there is no evidence that indicates the dependability of the Adhan on the Imam's permission.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.