Audio letter



An audio letter is an audio recording sent by postal mail to a recipient. The practice was more common when charges for long-distance telephone services were higher and before the widespread use of the Internet.

Discovered audio recordings offer a unique perspective into that time period and have often been used to present historical context in modern-day radio and television programs.

Media
Media used in recording audio letters include:
 * Wax cylinder
 * Reel to reel
 * Cassette tape
 * MiniDisc