Shaykh Al Uthaymeen said,

“It is befitting that the preference be given to the one with a good voice in regards to the Athaan, and a good voice is with three matters:
good presentation, good tone, and a strong voice. If these three are gathered in a Muathin, then it is the most complete that can be.” End translation. [Explanation of Bulughul Maraam 2/97]

Translated by

Majid Jawed Al-Afghanee
Abu Layl