A protocol for the collection of databases of audio recordings for forensic-voicecomparison research and practice is described. The protocol fulfils the following requirements. (1) The database contains at least two non-contemporaneous recordings of each speaker. (2) The database contains recordings of each speaker using different speaking styles, which are typical of speaking styles found in casework, and which are elicited as natural speech. (3) The database is usable for research and casework involving recording- and transmission-channel mismatch. The protocol includes three speaking tasks: (1) an informal telephone conversation; (2) an information exchange task over the telephone; and (3) a pseudopolice-style interview. Technical issues are also discussed.