(1) a peace officer while the peace officer is performing a duty or exercising authority imposed or granted by law;

(2) a person who is employed to provide emergency medical services including the transportation of ill or injured persons while the person is performing that duty;

(3) a fire fighter, while the fire fighter is fighting a fire or investigating the cause of a fire;

(4) an animal under the supervision of a peace officer, corrections officer, or jailer, if the person knows the animal is being used for law enforcement, corrections, prison or jail security, or investigative purposes; or

(5) the transmission of a communication over a citizen's band radio channel, the purpose of which communication is to inform or inquire about an emergency.

(b) An offense under this section is a Class B misdemeanor.

(c) It is a defense to prosecution under Subsection (a)(1) that the conduct engaged in by the defendant was intended to warn a person operating a motor vehicle of the presence of a peace officer who was enforcing Subtitle C, Title 7, Transportation Code.

(d) It is a defense to prosecution under this section that the interruption, disruption, impediment, or interference alleged consisted of speech only.

(e) In this section, "emergency" means a condition or circumstance in which an individual is or is reasonably believed by the person transmitting the communication to be in imminent danger of serious bodily injury or in which property is or is reasonably believed by the person transmitting the communication to be in imminent danger of damage or destruction.