Echo Lite privacy information: https://voicechanger.live/privacy#echo-lite

Firefox-specific clarification: voice effects and soundboard mixing run locally. Processed audio is supplied to the calling website you connect, which transmits it under its own privacy policy. Sign-in uses Echo's account service; session credentials remain in extension-origin storage. Optional technical and interaction reports require both Firefox data permission and Echo's own opt-in. You can disable them in Echo Settings or revoke the optional Firefox permission. The linked policy explains account data, service providers, retention and privacy rights.