INTERSPEECH 2009
10th Annual Conference of the International Speech Communication Association

Brighton, United Kingdom
September 6-10, 2009

Watermark Recovery from Speech Using Inverse Filtering and Sign Correlation

Robert Morris (1), Ralph Johnson (1), Vladimir Goncharoff (2), Joseph DiVita (1)

(1) SPAWAR Systems Center Pacific, USA
(2) University of Illinois at Chicago, USA

This paper presents an improved method for asynchronous embedding and recovery of sub-audible watermarks in speech signals. The watermark, a sequence of DTMF tones, was added to speech without knowledge of its time-varying characteristics. Watermark recovery began by implementing a synchronized zero-phase inverse filtering operation to decorrelate the speech during its voiced segments. The final step was to apply the sign correlation technique, which resulted in performance advantages over linear correlation detection. Our simulations include the effects of finite word length in the correlator.

Full Paper

Bibliographic reference.  Morris, Robert / Johnson, Ralph / Goncharoff, Vladimir / DiVita, Joseph (2009): "Watermark recovery from speech using inverse filtering and sign correlation", In INTERSPEECH-2009, 1311-1314.