.SPH File Extension

An SPH file is a waveform audio file created in the NIST SPHERE format, which is often used in speech recognition research. It usually contains a recording of a person speaking. SPH files can be provided as input to speech recognition systems.

SPHERE waveforms use 16-bit linear PCM and a 16KHz sample rate. They have a 1024 byte human-readable header that uses ASCII text formatting.

NOTE: SPH files can be converted to the .WAV format using a utility called sph_convert or SoX.

Because SPH files are uncommon, most popular media players cannot play them. However, you can play SPH audio in VLC media player, and you can convert SPH files to a more usable audio format using FFmpeg or SoX.

3D model effects file used by MikuMikuDance, a game where players control vocaloid virtual dancing characters; contains a .BMP image but uses the ".sph" extension instead; can used for adding a shiny look to 3D model features such as hair or clothes.

SPH files may also incorporate transparency (e.g., .PNG or .TGA images), but they are most commonly created from non-transparent bitmap images.

NOTE: To create a SPH file, draw a bitmap (".bmp") image with any graphics editor and rename the file extension to ".sph."