What is a NIST File?
NIST files contain recorded audio saved in the Speech Header Resource (SPHERE) format created by NIST to work with speech recognition software, like Hidden Markov Toolkit. Moreover, a NIST file also contains an ASCII-coded header file that includes metadata and other information, such as database type and version, audio channels, audio samples, sampling rate, etc.
Download NIST Sample Files
You can download .NIST sample files from below for testing purposes.