WMA to SPH Converter
Produce SPHERE speech research audio from WMA
Speech Corpus Format
SPH is standard for speech datasets — convert WMA for research use.
Dataset Preparation
Process entire WMA collections to SPH simultaneously.
Online Conversion
No speech toolkit needed — convert WMA to SPH in your browser.
How to convert WMA 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. Automatic speech recognition toolkits like Kaldi and HTK cannot import WMA — they require SPHERE-formatted input.
Kaldi, HTK, CMU Sphinx, NIST scoring tools, and most academic speech recognition frameworks expect SPH. It is the de facto standard for distributing speech evaluation datasets.
Yes — both names refer to the SPHERE format defined by the National Institute of Standards and Technology. SPH is the common file extension used across speech research communities.
SPHERE supports various sample rates and bit depths. The conversion preserves the audio fidelity present in your WMA files, which is typically sufficient for speech recognition tasks.
Yes — upload your full collection of WMA speech recordings and convertio.tools produces individual SPH files for each, which is ideal for preparing research corpora efficiently.