Is performing Adhan in a natural voice preferred over reciting it in a melodious voice?

In the question below: How are Adhan and Iqama recited in the Ibadi madhhab? One of the answers has the statement: > "Note that the adhan and iqamah are most correct if they are performed > in natural voice, and for the adahn especially it should be quite > -with small pauses- and clear voice (which is also preferred by imam Malik), not in a melodical voice as is usually done in the middle east > for example." As @Crimson points out in the comment section, do we have any point of reference which may explain if one is preferred over the other.