¶15 Extrinsic sources include legislative history. Id. The drafting records of the Electronic Surveillance Control Law state that the law “represents Wisconsin implementation of the electronic surveillance portion of [Title III],” the Omnibus Crime Control and Safe Streets Act of 1968.  Drafting File for ch. 427, Laws of 1969, Analysis by the Legislative Reference Bureau of 1969 A.B. 860, Legislative Reference Bureau, Madison, Wis. Although the legislative history of the Electronic Surveillance Control Law is silent on whether the definition of “oral communication” was meant to incorporate the speaker’s “reasonable expectation of privacy,” the legislative history of Title III provides guidance.State v. House, 2007 WI 79, ¶14, 302 Wis. 2d 1, 734 N.W.2d 140 (stating that because the Electronic Surveillance Control Law is “patterned after Title III[, our] interpretation . . . benefits from the legislative history and intent of Title III”). Our interpretation is assisted as well by the federal decisions that have considered Title III.State v. Gilmore, 201 Wis. 2d 820, 830, 549 N.W.2d 401 (1996) (recognizing that in interpreting the Electronic Surveillance Control Law, we may look to federal decisions interpreting Title III).