AV1 to SPH Converter
Extract NIST Sphere audio from AV1 video online
Speech Research Standard
SPH is the format for major speech corpora — converting from AV1 prepares audio for linguistic research and analysis.
Corpus Compatible
SPH files integrate with standard speech research tools like Kaldi, HTK, and NIST scoring utilities.
Private Files
AV1 uploads are erased right after conversion, and SPH outputs are deleted within 24 hours.
How to convert AV1 to SPH
Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.
Choose sph or any other format you need as a result (more than 200 formats supported)
Let the file convert and you can download your sph file right afterwards
About formats
Frequently Asked Questions
SPH (NIST Sphere) is the standard format for speech research corpora — used by linguistic datasets like TIMIT and Switchboard.
NIST Sphere tools, Kaldi, HTK, and SoX handle SPH files. It is standard in academic speech and language research.
SPH uses the NIST Sphere header format — the terms are often used interchangeably in speech research contexts.
Most speech corpora use 8 kHz or 16 kHz mono — standard rates for telephony and speech recognition data.
AV1 uploads are deleted immediately. SPH outputs are removed within 24 hours.