MKV to SPH Converter
Extract SPHERE audio from MKV for speech datasets
Research Standard
SPH is the gold standard for speech research corpora. Extract MKV audio in the format that speech recognition frameworks expect.
Corpus Building
Convert multiple MKV files to SPH at once. Efficient for assembling large speech datasets from video recordings.
Confidential Data
All MKV uploads are deleted after processing. SPH results are purged within 24 hours — sensitive speech data stays private.
How to convert MKV 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 (SPHERE) is the NIST standard for speech research corpora. Required by the Linguistic Data Consortium and major speech databases.
NIST SPeech HEader Resources tools, HTK, Kaldi, SoX, and academic speech processing frameworks handle SPH files as standard input.
Yes — SPHERE is widely used for speech recognition training data. Many foundational ASR datasets are distributed in SPH format.
Yes — SPH files include a text header with sample rate, channel count, encoding type, and other metadata useful for automated processing.
Yes — upload multiple MKV recordings and extract SPH audio from all of them. Ideal for building speech datasets from video sources.