An interpreter is subject to the provisions of these rules and applicable statutes relating to qualifications as an expert and the administration of an oath or affirmation to make a true interpretation.
Tenn. R. Evid. 604
Advisory Commission Comments.
Interpreters must fulfill two requirements: expertise in translating and willingness to swear or affirm. T.C.A. § 24-1-211 details the qualifications of sign language interpreters.
Advisory Commission Comment [2006].
The last word is changed from "translation" to "interpretation."