monotonist
/məˈnɒtənɪst/ /məˈnɒt(ə)nɪst/Chiefly derogatory. Now rare
noun
A person who speaks monotonously, or who is monotonous in some way; a person who desires or advocates monotony or uniformity.
Origin
Mid 18th century; earliest use found in Samuel Richardson (bap. 1689, d. 1761), printer and author. From monotone or monotony + -ist.