The paper examines the relative contribution that prominence effect and frequency effect make on the phonetic substances in a large-scale corpus of reading-style Standard Korean. Japanese has been reported to have a sentence-final shortening effect in reading style database, probably due to frequency effect with attenuated effect of prosodic prominence. To examine whether the Korean reading style has a similar effect to the Japanese sentence-final shortening, phonetic characteristics of declarative sentence-ending ‘ta’ are examined based on the speech of 10 male and 10 female Korean speakers drawn from a large-scale speech corpus. The result showed that the declarative-ending ‘ta’ is marked by higher F1 as well as longer duration and lower F0 than medial ‘ta,' which served as a reference. The paper ends with the discussion of phonological consequences that these phonetic prominence effects may have in a number of languages.