Federal Statutes re Audio interception, Not all sections are posted here:

TITLE 18. CRIMES AND CRIMINAL PROCEDURE
PART I. CRIMES
CHAPTER 119. WIRE AND ELECTRONIC COMMUNICATIONS INTERCEPTION AND INTERCEPTION
OF ORAL COMMUNICATIONS

§ 2510. Definitions

As used in this chapter [18 USCS §§ 2510 et seq.]--

(1) "wire communication" means any aural transfer made in whole or in part through the use of facilities for the transmission of communications by the aid of wire, cable, or other like connection between the point of origin and the point of reception (including the use of such connection in a switching station) furnished or operated by any person engaged in providing or operating such facilities for the transmission of interstate or foreign communications or communications affecting interstate or foreign commerce;

(2) "oral communication" means any oral communication uttered by a person exhibiting an expectation that such communication is not subject to interception under circumstances justifying such expectation, but such term does not  include any electronic communication;

(3) "State" means any State of the United States, the District of Columbia, the Commonwealth of Puerto Rico, and any territory or possession of the United States;

(4) "intercept" means the aural or other acquisition of the contents of any wire, electronic, or oral communication through the use of any electronic,  mechanical, or other device.

(5) "electronic, mechanical, or other device" means any device or apparatus which can be use dto intercept a wire, oral, or electronic communication other  than--

(a) any telephone or telegraph instrument, equipment or facility, or any component thereof,

(i) furnished to the subscriber or user by a provider of wire or electronic communication service in the ordinary course of its business and being used by the subscriber or user in the ordinary course of its business or furnished by such subscriber or user for connection to the facilities of such service and used in the ordinary course of its business; or

(ii) being used by a provider of wire or electronic communication service in the ordinary course of its business, or by an investigative or law enforcement officer in the ordinary course of his duties;

(b) a hearing aid or similar device being used to correct subnormal hearing to not better than normal;

(6) "person" means any employee, or agent of the United States or any State or political subdivision thereof, and any individual, partnership, association, joint stock company, trust, or corporation;

(7) "Investigative or law enforcement officer" means any officer of the United States or of a State or political subdivision thereof, who is empowered by law to conduct investigations of or to make arrests for offenses enumerated in this chapter [18 USCS §§ 2510 et seq.], and any attorney authorized by law to prosecute or participate in the prosecution of such offenses;

(8) "contents", when used with respect to any wire, oral, or electronic communication, includes any information concerning the substance, purport, or meaning of that communication;

(9) "Judge of competent jurisdiction" means--

(a) a judge of a United States district court or a United States court of appeals; and

(b) a judge of any court of general criminal jurisdiction of a State who is authorized by a statute of that State to enter orders authorizing interceptions of wire, oral, or electronic communications;

(10) "communication common carrier" has the meaning given that term in section 3 of the Communications Act of 1934 [47 USCS § 153];

(11) "aggrieved person" means a person who was a party to any intercepted wire, oral, or electronic communication or a person against whom the interception was directed;

(12) "electronic communication" means any transfer of signs, signals, writing, images, sounds, data, or intelligence of any nature transmitted in whole or in part by a wire, radio, electromagnetic, photoelectronic or photooptical system that affects interstate or foreign commerce, but does not include--

(A) any wire or oral communication;
(B) any communication made through a tone-only paging device;
(C) any communication from a tracking device (as defined in section 3117 of title [18 USCS § 3117]);or
(D) electronic funds transfer information stored by a financial institution in a communications system used for the electronic storage and transfer of funds;

(13) "user" means any person or entity who--

(A) uses an electronic communication service; and
(B) is duly authorized by the provider of such service to engage in such use;

(14) "electronic communications system" means any wire, radio, electromagnetic, photooptical or photoelectronic facilities for the transmission of wire or electronic communications, and any computer facilities or related electronic equipment for the electronic storage of such communications;

(15) "electronic communication service" means any service which provides to users thereof the ability to send or receive wire or electronic communications;

(16) "readily accessible to the general public" means, with respect to a radio communication, that such communication is not--

(A) scrambled or encrypted;
(B) transmitted using modulation techniques whose essential parameters have been withheld from the public with the intention of preserving the privacy of such communication;
(C) carried on a subcarrier or other signal subsidiary to a radio transmission;
(D) transmitted over a communication system provided by a common carrier, unless the communication is a tone only paging system communication; or
(E) transmitted on frequencies allocated under part 25, subpart D, E, or F of part 74, or part 94 of the Rules of the Federal Communications Commission, unless, in the case of a communication transmitted on a frequency allocated under part 74 that is not exclusively allocated to broadcast auxiliary services, the communication is a two-way voice communication by radio;
(F) [Deleted]

(17) "electronic storage" means--

(A) any temporary, intermediate storage of a wire or electronic communication incidental to the electronic transmission thereof; and
(B) any storage of such communication by an electronic communication service for purposes of backup protection of such communication;

(18) "aural transfer" means a transfer containing the human voice at any point between and including the point of origin and the point of reception;

(19) "foreign intelligence information", for purposes of section 2517(6) of this title [18 USCS § 2517(6)], means--

(A) information, whether or not concerning a United States person, that relates to the ability of the United States to protect against--

(i) actual or potential attack or other grave hostile acts of a foreign power or an agent of a foreign power;
(ii) sabotage or international terrorism by a foreign power or an agent of a foreign power; or
(iii) clandestine intelligence activities by an intelligence service or network of a foreign power or by an agent of a foreign power; or

(B) information, whether or not concerning a United States person, with respect to a foreign power or foreign territory that relates to--

(i) the national defense or the security of the United States; or
(ii) the conduct of the foreign affairs of the United States;

(20) "protected computer" has the meaning set forth in section 1030 [18 USCS § 1030]; and

(21) "computer trespasser"--

(A) means a person who accesses a protected computer without authorization and thus has no reasonable expectation of privacy in any communication transmitted to, through, or from the protected computer; and
(B) does not include a person known by the owner or operator of the protected computer to have an existing contractual relationship with the owner or operator of the protected computer for access to all or part of the protected computer.

§ 2511. Interception and disclosure of wire, oral, or electronic communications prohibited

(1) Except as otherwise specifically provided in this chapter [18 USCS §§ 2510 et seq.] any person who--

(a) intentionally intercepts, endeavors to intercept, or procures any other person to intercept or endeavor to intercept, any wire, oral, or electronic communication;

(b) intentionally uses, endeavors to use, or procures any other person to use or endeavor to use any electronic, mechanical, or other device to intercept any oral communication when--

(i) such device is affixed to, or otherwise transmits a signal through, a wire, cable, or other like connection used in wire communication; or
(ii) such device transmits communications by radio, or interferes with the transmission of such communication; or
(iii) such person knows, or has reason to know, that such device or any component thereof has been sent through the mail or transported in interstate or foreign commerce; or
(iv) such use or endeavor to use (A) takes place on the premises of any business or other commercial establishment the operations of which affect interstate or foreign commerce; or (B) obtains or is for the purpose of obtaining information relating to the operations of any business or other commercial establishment the operations of which affect interstate or foreign commerce; or
(v) such person acts in the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States;

(c) intentionally discloses, or endeavors to disclose, to any other person the contents of any wire, oral, or electronic communication, knowing or having reason to know that the information was obtained through the interception of a wire, oral, or electronic communication in violation of this subsection;

(d) intentionally uses, or endeavors to use, the contents of any wire, oral, or electronic communication, knowing or having reason to know that the information was obtained through the interception of a wire, oral, or electronic communication in violation of this subsection; or

(e) (i) intentionally discloses, or endeavors to disclose, to any other person the contents of any wire, oral, or electronic communication, intercepted by means authorized by sections 2511(2)(a)(ii), 2511(2)(b)-(c), 2511(2)(e), 2516, and 2518 of this chapter [18 USCS §§ 2511(2)(a)(ii), 2511(2)(b)-(c), 2511(2)(e), 2516, and 2518],

(ii) knowing or having reason to know that the information was obtained through the interception of such a communication in connection with a criminal investigation,

(iii) having obtained or received the information in connection with a criminal investigation, and (iv) with intent to improperly obstruct, impede, or interfere with a duly authorized criminal investigation, shall be punished as provided in subsection (4) or shall be subject to suit as provided in subsection (5).

(2) (a) (i) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] for an operator of a switchboard, or an officer, employee, or agent of a provider of wire or electronic communication service, whose facilities are used in the transmission of a wire or electronic communication, to intercept, disclose, or use that communication in the normal course of his employment while engaged in any activity which is a necessary incident to the rendition of his service or to the protection of the rights or property of the provider of that service, except that a provider of wire communication service to the public shall not utilize service observing or random monitoring except for mechanical or service quality control checks.

(ii) Notwithstanding any other law, providers of wire or electronic communication service, their officers, employees, and agents, landlords, custodians, or other persons, are authorized to provide information, facilities, or technical assistance to persons authorized by law to intercept wire, oral, or electronic communications or to conduct electronic surveillance, as defined in section 101 of the Foreign Intelligence Surveillance Act of 1978 [50 USCS § 1801] if such provider, its officers, employees, or agents, landlord, custodian, or other specified person, has been provided with--

(A) a court order directing such assistance signed by the authorizing judge, or

(B) a certification in writing by a person specified in section 2518(7) of this title [18 USCS § 2518(7)] or the Attorney General of the United States that no warrant or court order is required by law, that all statutory requirements have been met, and that the specified assistance is required,setting forth the period of time during which the provision of the information, facilities, or technical assistance is authorized and specifying the information, facilities, or technical assistance required. No provider of wire or electronic communication service, officer, employee, or agent thereof, or landlord, custodian,or other specified person shall disclose the existence of any interception or surveillance or the device used to accomplish the interception or surveillance with respect to which the person has been furnished an order or certification under this subparagraph, except as may otherwise be required by legal process and then only after prior notification to the Attorney General or to the principal prosecuting attorney of a State or any political subdivision of a State, as may be appropriate. Anysuch disclosure, shall render such person liable for the civil damages provided for in section 2520 [18USCS § 2520]. No cause of action shall lie in any court against any provider of wire or electronic communication service, its officers, employees, or agents, landlord, custodian, or other specified person for providing information, facilities, or assistance in accordance with the terms of a court order, statutory authorization, or certification under this chapter [18 USCS §§ 2510 et seq.].

(b) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] for an officer, employee, or agent of the Federal Communications Commission, in the normal course of his employment and in discharge of the monitoring responsibilities exercised by the Commission in the enforcement of chapter 5 of title 47 [47 USCS §§ 151 et seq.] of the United States Code, to intercept a wire or electronic communication, or oral communication transmitted by radio, or to disclose or use the information thereby obtained.

(c) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] for a person acting under color of law to intercept a wire, oral, or electronic communication, where such person is a party to the communication or one of the parties to the communication has given prior consent to such interception.

(d) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] for a person not acting under color of law to intercept a wire, oral, or electronic communication where such person is a party to the communication or where one of the parties to the communication has given prior consent to such interception unless such communication is intercepted for the purpose of committing any criminal or tortious act in violation of the Constitution or laws of the United States or of any State.

(e) Notwithstanding any other provision of this title or section 705 or 706 of the Communications Act of 1934 [47 USCS § 605 or 606], it shall not be unlawful for an officer, employee, or agent of the United States in the normal course of his official duty to conduct electronic surveillance, as defined in section 101 of the Foreign Intelligence Surveillance Act of 1978 [50 USCS § 1801], as authorized by that Act [50 USCS §§ 1801 et seq.].

(f) Nothing contained in this chapter or chapter 121 or 206 of this title [18 USCS §§ 2510 et seq., or 2701 et seq., or 3121 et seq.], or section 705 of the Communications Act of 1934 [47 USCS § 605], shall be deemed to affect the acquisition by the United States Government of foreign intelligence information from international or foreign communications, or foreign intelligence activities conducted in accordance with otherwise applicable Federal law involving a foreign electronic communications system, utilizing a means other than electronic surveillance as defined in section 101 of the Foreign Intelligence Surveillance Act of 1978 [50 USCS § 1801], and procedures in this chapter or chapter 121 or 206 of this title [18 USCS §§ 2510 et seq., or 2701 et seq., or 3121 et seq.] and the Foreign Intelligence Surveillance Act of 1978 [50 USCS §§ 1801 et seq.] shall be the exclusive means by which electronic surveillance, as defined in section 101 of such Act [50 USCS § 1801], and the interception of domestic wire, oral, and electronic communications may be conducted.

(g) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] or chapter 121 of this title [18 USCS §§ 2701 et seq.] for any person--

(i) to intercept or access an electronic communication made through an electronic communication system that is configured so that such electronic communication is readily accessible to the general public;

(ii) to intercept any radio communication which is transmitted--

(I) by any station for the use of the general public, or that relates to ships, aircraft, vehicles, or persons in distress;

(II) by any governmental, law enforcement, civil defense, private land mobile, or public safety communications system, including police and fire, readily accessible to the general public;

(III) by a station operating on an authorized frequency within the bands allocated to the amateur, citizens band, or general mobile radio services; or

(IV) by any marine or aeronautical communications system;

(iii) to engage in any conduct which--

(I) is prohibited by section 633 of the Communications Act of 1934 [47 USCS § 553]; or
(II) is excepted from the application of section 705(a) of the Communications Act of 1934 [47 USCS § 605(a)] by section 705(b) of that Act [47 USCS § 605(b)];

(iv) to intercept any wire or electronic communication the transmission of which is causing harmful interference to any lawfully operating station or consumer electronic equipment, to the extent necessary to identify the source of such interference; or
(v) for other users of the same frequency to intercept any radio communication made through a system that utilizes frequencies monitored by individuals engaged in the provision or the use of such system, if such communication is not scrambled or encrypted.

(h) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.]--

(i) to use a pen register or a trap and trace device (as those terms are defined for the purposes of chapter 206 (relating to pen registers and trap and trace devices) of this title) [18 USCS §§ 3121 et seq.]; or
(ii) for a provider of electronic communication service to record the fact that a wire or electronic communication was initiated or completed in order to protect such provider, another provider furnishing service toward the completion of the wire or electronic communication, or a user of that service, from fraudulent, unlawful or abusive use of such service.

(i) It shall not be unlawful under this chapter [18 USCS §§ 2510 et seq.] for a person acting under color of law to intercept the wire or electronic communications of a computer trespasser transmitted to, through, or from the protected computer, if--

(I) the owner or operator of the protected computer authorizes the interception of the computer trespasser's communications on the protected computer;
(II) the person acting under color of law is lawfully engaged in an investigation;
(III) the person acting under color of law has reasonable grounds to believe that the contents of the computer trespasser's communications will be relevant to the investigation; and
(IV) such interception does not acquire communications other than those transmitted to or from the computer trespasser.

(3)
(a) Except as provided in paragraph

(b) of this subection, a person or entity providing an electronic communication service to the public shall not intentionally divulge the contents of any communication (other than one to such person or entity, or an agent thereof) while in transmission on that service to any person or entity other than an addressee or intended recipient of such communication or an agent of such addressee or intended recipient.

(b) A person or entity providing electronic communication service to the public may divulge the contents of any such communication--

(i) as otherwise authorized in section 2511(2)(a) or 2517 of this title [18 USCS § 2511(2)(a) or 2517];
(ii) with the lawful consent of the originator or any addressee or intended recipient of such communication;
(iii) to a person employed or authorized, or whose facilities are used, to forward such communication to its destination; or
(iv) which were inadvertently obtained by the service provider and which appear to pertain to the commission of a crime, if such divulgence is made to a law enforcement agency.

(4)

(a) Except as provided in paragraph

(b) of this subsection or in subsection

(5), whoever violates subsection (1) of this section shall be fined under this title or imprisoned not more than five years, or both.

(b) Conduct otherwise an offense under this subsection that consists of or relates to the interception of a satellite transmission that is not encrypted or scrambled and that is transmitted--

(i) to a broadcasting station for purposes of retransmission to the general public; or
(ii) as an audio subcarrier intended for redistribution to facilities open to the public, but not including data transmissions or telephone calls,is not an offense under this subsection unless the conduct is for the purposes of direct or indirect commercial advantage or private financial gain.

(c) [Redesignated]

(5)

(a) (i) If the communication is--

(A) a private satellite video communication that is not scrambled or encrypted and the conduct in violation of this chapter [18 USCS §§ 2510 et seq.] is the private viewing of that communication and is not for a tortious or illegal purpose or for purposes of direct or indirect commercial advantage or private commercial gain; or

(B) a radio communication that is transmitted on frequencies allocated under subpart D of part 74 of the rules of the Federal Communications Commission that is not scrambled or encrypted and the conduct in violation of this chapter [18 USCS §§ 2510 et seq.] is not for a tortious or illegal purpose or for purposes of direct or indirect commercial advantage or private commercial gain,then the person who engages in such conduct shall be subject to suit by the Federal Government in a court of competent jurisdiction.

(ii) In an action under this subsection--

(A) if the violation of this chapter [18 USCS §§ 2510 et seq.] is a first offense for the person under paragraph (a) of subsection (4) and such person has not been found liable in a civil action under section 2520 of this title [18 USCS § 2520], the Federal Government shall be entitled to appropriate
injunctive relief; and

(B) if the violation of this chapter [18 USCS §§ 2510 et seq.] is a second or subsequent offense under paragraph (a) of subsection (4) or such person has been found liable in any prior civil action under section 2520 [18 USCS § 2520], the person shall be subject to a mandatory $ 500 civil fine.

(b) The court may use any means within its authority to enforce an injunction issued under paragraph

(ii)(A), and shall impose a civil fine of not less than $ 500 for each violation of such an injunction.§ 2512. Manufacture, distribution, possession, and advertising of wire, oral, or electronic communication intercepting devices prohibited

(1) Except as otherwise specifically provided in this chapter [18 USCS §§ 2510 et seq.], any person who intentionally--

(a) sends through the mail, or sends or carries in interstate or foreign commerce, any electronic, mechanical, or other device, knowing or having reason to know that the design of such device renders it primarily useful for the purpose of the surreptitious interception of wire, oral, or electronic
communications;

(b) manufactures, assembles, possesses, or sells any electronic, mechanical, or other device, knowing or having reason to know that the design of such device renders it primarily useful for the purpose of the surreptitious interception of wire, oral, or electronic communications, and that such device or any component thereof has been or will be sent through the mail or transported in
interstate or foreign commerce; or

(c) places in any newspaper, magazine, handbill, or other publication or disseminates by electronic means any advertisement of--

(i) any electronic, mechanical, or other device knowing or having reason to know that the design of such device renders it primarily useful for the purpose of the surreptitious interception of wire, oral, or electronic communications; or
(ii) any other electronic, mechanical, or other device, where such advertisement promotes the use of such device for the purpose of the surreptitious interception of wire, oral, or electronic communications,knowing the content of the advertisement and knowing or having reason to know that such advertisement will be sent through the mail or transported in interstate or foreign commerce,
shall be fined under this title or imprisoned not more than five years, or both.

(2) It shall not be unlawful under this section for--

(a) a provider of wire or electronic communication service or an officer, agent, or employee of, or person under contract with, such a provider, in the normal course of the business of providing that wire or electronic communication service, or

(b) an officer, agent, or employee of, or a person under contract with, the United States, a State, or a political subdivision thereof, in the normal course of the activities of the United States, a State, or a political subdivision thereof,to send through the mail, send or carry in interstate or foreign commerce, or manufacture, assemble, possess, or sell any electronic, mechanical, or other device knowing or having reason to know that the design of such device renders it primarily useful for the purpose of the surreptitious interception of wire, oral, or electronic communications.

(3) It shall not be unlawful under this section to advertise for sale a device described in subsection (1) of this section if the advertisement is mailed, sent, or carried in interstate or foreign commerce solely to a domestic provider of wire or electronic communication service or to an agency of the United States, a State, or a political subdivision thereof which is duly authorized to use such device.

§ 2513. Confiscation of wire, oral, or electronic communication intercepting devices

Any electronic, mechanical, or other device used, sent, carried, manufactured, assembled, possessed, sold, or advertised in violation of section 2511 or section 2512 of this chapter [18 USCS § 2511 or 2512] may be seized and forfeited to the United States. All provisions of law relating to

(1) the seizure, summary and judicial forfeiture, and condemnation of vessels, vehicles, merchandise, and baggage for violations of the customs laws contained in title 19 of the United States Code,

(2) the disposition of such vessels, vehicles, merchandise, and baggage or the proceeds from the sale thereof,

(3) the remission or mitigation of such forfeiture,

(4) the compromise of claims, and

(5) the award of compensation to informers in respect of such forfeitures, shall apply to seizures and forfeitures incurred, or alleged to have been incurred, under the provisions of this section, insofar as applicable and not inconsistent with the provisions of this section; except that such duties as are imposed upon the collector of customs or any other person with respect to the seizure and forfeiture of vessels, vehicles, merchandise, and baggage under the provisions of the customs laws contained in title 19 of the United States Code shall be performed with respect to seizure and forfeiture of electronic, mechanical, or other intercepting devices under this section by such officers, agents, or other persons as may be authorized or designated for that purpose by the Attorney General.

§ 2515. Prohibition of use as evidence of intercepted wire or oral communications

Whenever any wire or oral communication has been intercepted, no part of the contents of such communication and no evidence derived therefrom may be received in evidence in any trial, hearing, or other proceeding in or before any court, grand jury, department, officer, agency, regulatory body, legislative committee, or other authority of the United States, a State, or a political subdivision thereof if the disclosure of that information would be in violation of this chapter [18 USCS §§ 2510 et seq.].