Recording: Legal Issues
The Reporters' Committee for Freedom of the Press (RCFP) has prepared a web document entitled "Can We Tape"? A Practical Guide to Taping Phone Calls and In-Person Conversations in the 50 states and D.C."
The legality of voice recording in the U.S. is governed by laws (Federal and State) aimed at preventing eavesdropping. The key legal point, from the perspective of language documentation projects, is very simple:
Generally, you may record, film, broadcast or amplify any conversation where all the parties to it consent. It is always legal to tape or film a face-to-face interview when your recorder or camera is in plain view. The consent of all parties is presumed in these instances.
In 38 of 50 states, the consent of only one party is required to make it legal to record a conversation. This is also the Federal law, which applies to Washington D.C. One linguist's opinion (Mark Liberman's "Concerning the Recording and Publications of Primary Language Materials" at Exploration 2000) is that language documentation projects should always obtain the consent of everyone being recorded, for ethical reasons.
Note that the laws with respect to video recording are generally more flexible. As the RCFP page says:
The use of hidden cameras is only covered by the wiretap and eavesdropping laws if the camera also records an audio track. However, a handful of states have adopted laws specifically banning the use of video and still cameras where the subject has an expectation of privacy, although some of the laws are much more specific. Maryland's law, for example, bans the use of hidden cameras in bathrooms and dressing rooms.
The linguist however does not think that surreptitious video recording would be an appropriate practice in language documentation projects, even though it will usually be legal, at least according to U.S. law (Mark Liberman's "Concerning the Recording and Publications of Primary Language Materials" at Exploration 2000).
For recordings made outside the U.S., the applicable law (if any) will presumably be the law of the place where the recordings are made. It seems unlikely that there is any place where it is illegal to record an interaction if all parties consent.
Note that this section only deals with the question of whether it is legal to make a recording, and not with the question of who owns what aspects of the result, or whether it is legitimate to distribute or publish the result.