GSM 06.10 Lossy Speech Compression. A lossy format for compressing speech which is used in the Global Standard for Mobile telecommunications (GSM). It’s good for its purpose, shrinking audio data size, but it will introduce lots of noise when a given audio signal is encoded and decoded multiple times. This format is used by some voice mail applications. It is rather CPU intensive.
an audio format from Apple that was developed to remove the limitations of AIFF and WAV formats. This is a container that can store sound encoded by various algorithms and track metadata. Its characteristic feature - the format doesn’t have limitations on file size and so this allows one to store infinitely long recordings.