وَعَنْ أَبِي مَحْذُورَةَ رضى الله عنه
«أَنَّ اَلنَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَعْجَبَهُ صَوْتُهُ، فَعَلَّمَهُ اَلْآذَانَ»
The Prophet (sallallahu alayhi wa sallam) liked his voice, so he taught him the Adhan (call to prayer).
Bulugh al-Maram 222, Book 2, The Book of Prayer, Hadith 43. 1 min read