Audio surveillance laws are federal and state laws that determine how someone may listen to and / or record audio. Generally, these laws cover whether someone would have a reasonable expectation of privacy and the type of consent that must be obtained. These laws also determine if and when law enforcement must obtain a warrant. States are either one-party or two-party consent states. This means that one person or both people involved in the conversation must give permission for it to be recorded. Third-parties who aren’t involved in the conversation may not have a legal right to listen in or record audio between others.