N.H. Rev. Stat. Ann. § 570-A:9-b

Notwithstanding any other provision of this chapter, an investigative or law enforcement officer supervising an interception under this chapter in which the intercepted communication is in a code or foreign language may utilize the assistance and participation of a qualified interpreter to translate the language being used into English. Such interpreter, before entering upon his or her duties, shall take an oath that he or she will make a true interpretation in an understandable manner to the best of his or her skill and judgment.