orthoepy
noun
or·tho·epy ˈȯr-thə-ˌwe-pē 
ȯr-ˈthō-ə-pē
ȯr-ˈthō-ə-pē 1
: the customary pronunciation of a language
2
: the study of the pronunciation of a language
orthoepic
ˌȯr-thə-ˈwe-pik
adjective orthoepically
ˌȯr-thə-ˈwe-pi-k(ə-)lē
adverb orthoepist
ˈȯr-thə-ˌwe-pist ȯr-ˈthō-ə-pist
noun ȯr-ˈthō-ə-pist 
Word History
Etymology
New Latin orthoepia, from Greek orthoepeia, from orth- + epos word — more at voice
First Known Use
1640, in the meaning defined at sense 2