This case involves the government’s application for an order authorizing the installation and use of a pen register1 and directing the Southwestern Bell Telephone Company to provide facilities, information and technical assistance to special agents of the Federal Bureau of Investigation in the installation and use of the device. Southwestern Bell contends in this appeal that the district court2 erred in authorizing the use of the pen register and in ordering appellant to provide technical assistance to the government. We affirm the order of the district court.
In an in camera ex parte proceeding on July 26, 1976, the United States Attorney sought and received the permission of the district court to install and monitor a pen register device to identify the outgoing telephone numbers dialed from a particular telephone. An affidavit signed by a Federal Bureau of Investigation agent set forth facts which disclosed probable cause to believe the telephone in question was being used to further the commission of a racketeering offense prohibited by Title 18, United States Code. Although the offense is one for which governmental electronic surveillance is permitted by the provisions of Title III of the Omnibus Crime Control and Safe Streets Act of 1968,18 U.S.C. §§ 2510-2520, the United States Attorney did not make the application thereunder. The order issued by the district court affirmatively required Southwestern Bell Telephone Company to “furnish the applicant forthwith all facilities including lease lines, information, including the identification of lease line pairs, subscriber pairs and the location of a suitable junction box where a connection can occur, and technical assistance necessary to accomplish the interception unobtrusively and with a minimum of interference with the services that such carrier is providing.”3
On July 27,1976, the appellant moved the district court to reconsider its order and to remove the appellant from the provisions of the order. On July 30, 1976, the district court denied appellant’s motion and held appellant in contempt for failure to comply with the order of July 26,1976. No citation was issued and compliance with the order was stayed pending appeal to this court.4 We will consider separately the two substantial questions raised on this appeal: first, whether the district court erred in holding that pen register orders are not covered by Title III of the Omnibus Crime Control and Safe Streets Act of 1968; and second, whether it erred in ordering the appellant to provide technical assistance to the government.
*245I.
Title III of the Omnibus Crime Control and Safe Streets Act of 1968, 18 U.S.C. §§ 2510-2520, prescribes the procedure for securing judicial authority to intercept wire communications in the investigation of specified serious offenses. United States v. Giordano, 416 U.S. 505, 507, 94 S.Ct. 1820, 40 L.Ed.2d 341 (1974). Appellant contends that pen register devices fall within the purview of Title III. The greater weight of authority, however, is contrary to that position. United States v. Giordano, supra, 416 U.S. at 553-554, 94 S.Ct. 1820 (Powell, J., concurring in part and dissenting in part); United States v. Illinois Bell Telephone Co., 531 F.2d 809, 812 (7th Cir. 1976); United States v. Clegg, 509 F.2d 605, 610 (5th Cir. 1975); United States v. Falcone, 505 F.2d 478, 482 (3d Cir. 1974), cert. denied, 420 U.S. 955, 95 S.Ct. 1339, 43 L.Ed.2d 432 (1975); United States v. Brick, 502 F.2d 219, 223 (8th Cir. 1974); United States v. Finn, 502 F.2d 938, 942 (7th Cir. 1974); Korman v. United States, 486 F.2d 926, 931 (7th Cir. 1973).
Title Ill’s applicability to a pen register device turns on the definition of an “interception” of wire communications. “Interception” as defined by 18 U.S.C. § 2510(4) is “the aural acquisition of the contents of any wire or oral communication through the use of any electronic, mechanical, or other device” (emphasis added). An “aural acquisition” by definition engages the sense of hearing. United States v. Falcone, supra, 505 F.2d at 482. The pen register device does not possess this sense. It acquires its information (the recording of numbers dialed at a telephone) by interpreting and printing out electric pulses. The conclusion is therefore inescapable that a pen register device falls outside the ambit of Title III. This conclusion is bolstered by the legislative history of the Act. As Mr. Justice Powell stated in a concurring and dissenting opinion, joined by Chief Justice Burger, Mr. Justice Blackmun, and Mr. Justice Rehnquist, in United States v. Giordano, supra, 416 U.S. at 553, 94 S.Ct. at 1844:
The installation of a pen register device to monitor and record the numbers dialed from a particular telephone line is not governed by Title III. This was the conclusion of the District Court in the instant case and of the courts in United States v. King, 335 F.Supp. 523, 548-549 (SD Cal.1971), and in United States v. Vega, 52 F.R.D. 503, 507 (EDNY 1971). This conclusion rests on the fact that the device does not hear sound and therefore does not accomplish any “interception” of wire communications as that term is defined by 18 U.S.C. § 2510(4) — “the aural acquisition of the contents of any wire or oral communication through the use of any electronic, mechanical, or other device” (emphasis added). Any doubt of the correctness of this interpretation is allayed by reference to the legislative history of Title III. The Report of the Senate Committee on the Judiciary in discussing the scope of the statute explicitly states “[t]he use of a ‘pen register,’ for example, would be permissible.” S.Rep.No.1097, 90th Cong., 2d Sess., 90 (1968).
It is our view that the propriety of a pen register’s usage depends entirely upon compliance with the Fourth Amendment rather than Title III. United States v. Giordano, supra, 416 U.S. at 553-54, 94 S.Ct. 1820 (Powell, J., concurring in part and dissenting in part); United States v. John, 508 F.2d 1134, 1141 (8th Cir.), cert. denied, 421 U.S. 962, 95 S.Ct. 1948, 44 L.Ed.2d 448 (1975). The court’s power to order pen register surveillance is the equivalent of the power to order a search- warrant and is inherent in the district court.5 It is clear upon the record before us that the district court issued the order based upon a showing of probable cause. We conclude that the district court’s approach, with all of the attendant Fourth Amendment safeguards, was a valid exercise of authority. Application of the United States in re Order Au*246thorizing the Use of a Pen Register, 538 F.2d 956 (2d Cir. 1976); United States v. Illinois Bell Telephone Co., supra, 531 F.2d at 812-13.
II.
Appellant’s second contention is that the district court erred in ordering the appellant to provide technical assistance to the government.6 In support of this argument appellant cites Application of the United States, 427 F.2d 639 (9th Cir. 1970), and the Congressional action which followed. In that case the government had obtained a valid wiretap order pursuant to Title III and the question arose whether the district court had inherent authority to compel the cooperation of the telephone company. The Ninth Circuit concluded that the district court had no statutory or inherent authority to enter such an order. Application of United States, supra, 427 F.2d at 644. Soon after this decision Congress adopted amendments to Title II which authorized the district court to direct that a communication common carrier furnish all information, facilities, and technical assistance necessary. 18 U.S.C. § 2518(4). Appellant argues that the Congressional reaction to the Ninth Circuit decision was in the nature of an acceptance of the views expressed therein. The clear Congressional intent, according to appellant, was to authorize active participation on the part of the telephone company only in connection with orders issued under Title III.
An equally persuasive argument can be made, however, that the Congressional reaction was more in the nature of an overruling of the Ninth Circuit opinion. Congress may have originally presumed that power existed in the courts to compel compliance with orders authorizing electronic surveillance. United States v. Illinois Bell Telephone Co., supra, 531 F.2d at 813-14. When faced with the Ninth Circuit decision, Congress reacted by legislating in an area where they had presumed the court’s inherent power was sufficient. In this light Congress’ amendments to Title III provide “strong and persuasive authority, by analogy, for the proposition that district courts in the area of electronic surveillance, inherently have power to effectively compel compliance with validly issued orders.” United States v. Illinois Bell Telephone Co., supra, 531 F.2d at 814.
More important than the interpretation of Congressional action, however, is the district court’s finding in its memorandum of July 30, 1976. There it was stated “[t]hat without the information, leased lines and assistance [of Southwestern Bell Telephone Company] the Federal Bureau of Investigation cannot carry out the Order of this Court.” In view of this finding, the inherent power of the district court to order pen register surveillance would be a nullity without the authority to compel the assistance of the telephone company. It is in a sense concomitant of the power to authorize pen register surveillance. United States v. Illinois Bell Telephone Co., supra, 531 F.2d at 814. Therefore, we hold as did the Seventh Circuit, that the district court had inherent authority to order the telephone company’s assistance.7 United States v. Il*247linois Bell Telephone Co., supra, 531 F.2d at 811. To hold other otherwise would effectively allow the telephone company rather than the district court to decide when pen register surveillance should be used. On the record before us we find no abuse of discretion by the district court in directing that the telephone company render assistance. See Application of the United States in re Order Authorizing the Use of a Pen Register, supra, 538 F.2d at 964-66 (Mansfield, J., dissenting).
Affirmed.
. The pen register is a mechanical device whose basic function is to record numbers dialed at a telephone. Although pen register devices available to federal agents have the capability of audio interception of the conversation of the parties to a call, in this case the district court’s order does not permit monitoring or recording the conversations themselves. The federal agent stated during the ex parte proceeding that he would disable these features of the pen register.
. The Honorable H. Kenneth Wangelin, United States District Judge for the Eastern District of Missouri.
. The order also provided that the furnishing of such facilities or technical assistance was to be compensated for by the applicant at the prevailing rates.
. Appellant contends in this appeal that the district court erred in holding Southwestern Bell Telephone Company in contempt. Although this finding of contempt is questionable in light of appellant’s prompt motion for reconsideration, we refuse to reverse the finding since no sanctions were imposed and compliance with the order was stayed pending appeal.
. The unusual character and technological advances of electronic communications have occasioned the surfacing of this inherent authority. Although Fed.R.Crim.P. 41 governs the search and seizure of tangible objects, it is, by analogy, supportive of our conclusion.
. Appellant’s contention is based in part on a concern for possible exposure to civil and criminal liability. Although this question is not before us, it should be noted that 18 U.S.C. § 2520 states that “[a] good faith reliance on a court order * * * shall constitute a complete defense to any civil or criminal action brought under this chapter or under any other law.” The district court also found, in its memorandum filed July 30, 1976, and incorporated in its order of the same date, that compliance by Southwestern Bell Telephone Company with the court’s order would be a complete defense to any claim of criminal or civil liability.
. An argument can be made that the All Writs Act gives the district court the power to compel the telephone company’s assistance. As stated by the Seventh Circuit:
Therefore, analogous authority for the proposition that the telephone company cannot frustrate the exercise of the district court’s order by refusing to make available its facilities and know-how, is the All Writs Act. The All Writs Act, 28 U.S.C. § 1651 provides in pertinent part:
(a) The Supreme Court and all courts established by Act of Congress may issue all writs necessary or appropriate in aid of their re*247spective jurisdictions and agreeable to the usages and principles of law.
This statute allows a district court to defend a proper exercise of its jurisdiction, although it does not supply jurisdiction.
United States v. Illinois Bell Telephone Co., supra, 531 F.2d at 814 (footnote omitted).
The Second Circuit assumed arguendo that a district court has inherent discretionary authority or discretionary power under the All Writs Act to compel technical assistance by the telephone company, but concluded that in the absence of specific and properly limited Congressional action it was an abuse of discretion to order the telephone company to furnish technical assistance. Application of the United States in re Order Authorizing the Use of a Pen Register, supra, 538 F.2d at 960-63.