An NIST is a type of audio file that is used for research into speech recognition. These files use the format of the National Institute of Standards and Technology’s Speech Header Resources. They usually consist of an audio clip of a person speaking, which then serves as input to improve the technology that recognizes human speech. NIST files also include the metadata of the file, such as database information, sample rate, and the number of audio samples and channels. These files, which are still uncommon, have been in use since 1995 and are intended for both storage and distribution on a Windows operating system.