542.400.  Definitions. — As used in sections 542.400 to 542.422, the following words and phrases mean:

  (1)  "Aggrieved person", a person who was a party to any intercepted wire communication or a person against whom the interception was directed;

  (2)  "Communication common carrier", an individual or corporation undertaking to transport messages for compensation;

  (3)  "Contents", when used with respect to any wire communication, includes any information concerning the identity of the parties, the substance, purport, or meaning of that communication;

  (4)  "Court of competent jurisdiction", any circuit court having general criminal jurisdiction within the territorial jurisdiction where the communication is to be intercepted including any circuit judge specially assigned by the supreme court of Missouri pursuant to section 542.404;

  (5)  "Electronic, mechanical, or other device", any device or apparatus which can be used to intercept a wire communication other than:

  (a)  Any telephone or telegraph instrument, equipment or facility, or any component thereof, owned by the user or furnished to the subscriber or user by a communications common carrier in the ordinary course of its business and being used by the subscriber or user in the ordinary course of its business or being used by a communications common carrier in the ordinary course of its business or by an investigative office or law enforcement officer in the ordinary course of his duties; or

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

  (6)  "Intercept", the aural acquisition of the contents of any wire communication through the use of any electronic or mechanical device, including but not limited to interception by one spouse of another spouse;

  (7)  "Investigative officer" or "law enforcement officer or agency", any officer or agency of this state or a political subdivision of this state, who is empowered by law to conduct investigations of or to make arrests for offenses enumerated in sections 542.400 to 542.422, and any attorney authorized by law to prosecute or participate in the prosecution of such offenses;

  (8)  "Oral communication", any communication uttered by a person exhibiting an expectation that such communication is not subject to interception under circumstances justifying such expectation;

  (9)  "Person", any employee, or agent of this state or political subdivision of this state, and any individual, partnership, association, joint stock company, trust, or corporation;

  (10)  "Prosecuting attorney", the elected prosecuting attorney of the county or the circuit attorney of any city not contained within a county;

  (11)  "State", the^* state of Missouri and political subdivisions of the state;

  (12)  "Wire communication", any communication 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 as a common carrier in providing or operating such facilities for the transmission of local, state or interstate communications.