Microsoft patents audio watermarking that survives editing
Microsoft has filed a patent for a method to hide digital watermarks inside audio files by splitting the sound into two parts: the tone and the noise. It embeds two different types of hidden codes into these parts using specific keys, making the watermark harder to remove if the audio is compressed or edited.
In the filing’s own words
Methods and systems for processing digital audio are disclosed. A digital audio file is received and linear predictive coding (LPC) analysis is performed to decompose the digital audio file into a spectral envelope signal and an excitation signal. A spread spectrum watermark is generated using a first watermark key and the spectral envelope signal, and a self-correlated watermark is generated using a second watermark key and the excitation signal. The spread spectrum watermark and the self-correlated watermark are embedded into the digital audio file. LPC synthesis is performed to combine the spectral envelope signal with the embedded spread spectrum watermark and the excitation signal with the embedded self-correlated watermark to produce a watermarked digital audio file.
What exactly they claim (claim 1)
1. A method, comprising: receiving a digital audio file; performing linear predictive coding (LPC) analysis on the digital audio file to decompose the digital audio file into a spectral envelope signal and an excitation signal; generating a spread spectrum watermark using a first watermark key and the spectral envelope signal; generating a self-correlated watermark using a second watermark key and the excitation signal; embedding the spread spectrum watermark into the digital audio file; embedding the self-correlated watermark into the digital audio file; and performing LPC synthesis to combine the spectral envelope signal with the spread spectrum watermark, and the excitation signal with the self-correlated watermark, to produce a watermarked digital audio file.
Facts
- Company
- Microsoft (Microsoft Technology Licensing, LLC)
- Official title
- ROBUST AUTHENTICATION OF DIGITAL AUDIO
- Publication number
- US20260311711A1
- Application number
- 19705728
- Filed
- Jun 11, 2026
- Published
- Oct 8, 2026
- Inventors
- 4
- Claims
- 20
Classified under
G10L 19/018 Physics & computingG10L 25/51 Physics & computingMore from Microsoft in Audio & voice
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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.