Play SPH Files Online

About SPH Files

An .sph (or .nist) file is an audio file saved in the NIST SPHERE (SPH) format, a standardized audio format the U.S. National Institute of Standards and Technology (NIST) developed for speech data storage and exchange. SPH files typically contain uncompressed or lightly compressed audio along with a detailed text-based header that stores metadata, such as sample rate, encoding type, channel count, and recording conditions.

SPH files are most commonly encountered in linguistic research, speech recognition development, and government or academic speech corpora. They have been widely used in projects involving speaker identification, transcription, and acoustic analysis, including datasets created for universities, research labs, and law enforcement agencies. While the format is less common in consumer audio workflows, it remains important for archivists, researchers, and developers working with legacy or standardized speech datasets. Users can open and play .sph files on FileHelper.com by dragging them to this page.

Converting SPH Files

You can convert .sph or .nist files to other formats to improve compatibility:

• Converting to MP3: Converts SPH speech audio into a universally compatible format that can be played on most devices and media players, with some loss of detail due to compression.
• Converting to AAC: Produces a compact audio file that maintains good speech clarity while offering broad support across modern devices and streaming services.