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`UNITED STATES PATENT AND TRADEMARK OFFICE
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`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`
`
`VERANCE CORP.,
`
`Petitioner,
`v.
`MZ AUDIO SCIENCES, LLC,
`
`Patent Owner.
`
`
`
`
`
`
`
`
`CASE: IPR2022-01544
`Patent No. 7,289,961 B2
`
`
`
`
`
`
`PETITIONER’S REPLY TO PATENT OWNER’S RESPONSE
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`

`

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`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
`TABLE OF CONTENTS
`
` .................................................................................................. III 
`EXHIBIT LIST
`I. 
`INTRODUCTION ............................................................................................. 1 
`II.  PATENT OWNER FAILS TO ADDRESS THE BENEFITS GAINED
`BY THE PROPOSED COMBINATION ................................................................. 1 
`III.  PATENT OWNER’S ARGUMENTS AGAINST THE SRINIVASAN-
`CABOT-KUDUMAKIS COMBINATION ARE CONTRADICTED BY
`THE EVIDENCE OF RECORD .............................................................................. 3 
`A. 
`Srinivasan does not mandate using 4.8-6kHz range ............................ 3 
`B. 
`Srinivasan does not require absolute inaudibility ................................ 4 
`C. 
`The combinations in Grounds 1 and 2 maintain low audibility ........... 5 
`D. 
`Patent Owner ignores Cabot’s explanations and conclusions that
`phase shifts are very hard to detect ...................................................... 6 
`The ’961 patent’s claims do not recite any limitations related to
`a particular audibility level ................................................................... 8 
`The combination does not need to produce an optimum system ....... 10 
`F. 
`IV.  KUDUMAKIS DOES NOT TEACH AWAY FROM THE PROPOSED
`COMBINATION .................................................................................................. 11 
`V.  HOBSON IS ANALOGOUS ART ................................................................. 12 
`A.  Hobson is from the same field of endeavor ....................................... 13 
`B. 
`Hobson is reasonably pertinent to the problem solved in the ’961
`patent .................................................................................................. 15 
`VI.  GROUND 3 COMBINATION RENDERS THE CLAIMS OBVIOUS ........ 18 
`A. 
`Tilki’s technique was fast and simple ................................................ 18 
`B. 
`The combination with Cabot did not produce audibility issues,
`and a POSA would have been motivated by the advantages
`gained by the combination ................................................................. 19 
`Patent Owner’s FFT bin spacing assertions are unavailing ............... 20 
`The challenged claims do not recite a bitrate requirement and the
`combination provides adequate watermarking capacity .................... 22 
`
`E. 
`
`C. 
`D. 
`
`- i -
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`

`

`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`VII. OTHER INACCURACIES AND MISSTATEMENTS ................................. 24 
`VIII.  CONCLUSION .............................................................................................. 28 
`
`
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`- ii -
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`EXHIBIT LIST
`
`Description
`Exhibit
`Ex. 1001 U.S. Patent No. 7,289,961 (“’961 Patent”)
`
`Ex. 1002 Prosecution History of U.S. Patent No. 7,289,961
`
`Ex. 1003 Declaration of Michael Scordilis, Ph.D.
`
`Ex. 1004 Curriculum Vitae of Michael Scordilis, Ph.D.
`
`Ex. 1005 U.S. Patent No. 6,272,176 (“Srinivasan”)
`
`Ex. 1006 Richard C. Cabot et al., “Detection of phase shifts in harmonically
`related tones,” in Journal of the Audio Engineering Society, vol. 24,
`no. 7, pp. 568-571 (Sept. 1976) (“Cabot”) (from pages 8-11 of the
`Rachel J. Watters Declaration, Ex. 1009)
`
`Ex. 1007 PCT Publication WO 01/58063 (“Kudumakis”)
`
`Ex. 1008
`
`John F. Tilki et al., “Encoding a hidden auxiliary channel onto a
`digital audio signal using psychoacoustic masking,” in Proceedings
`IEEE SOUTHEASTCON ’97. ‘Engineering the New Century,’ pp.
`331-333 (1997) (“Tilki”)
`
`Ex. 1009 Declaration of Rachel J. Watters Relating to Exhibit 1006
`
`Ex. 1010 U.S. Patent No. 4,546,779
`
`Ex. 1011 Christine I. Podilchuk et al., “Digital Watermarking: Algorithms and
`Applications,” in IEEE Signal Processing Magazine, vol. 18, no. 4,
`pp. 33-46 (July 2001) (“Podilchuk”) (from pages 6-21 of the Rachel
`J. Watters Declaration, Ex. 1034)
`
`Ex. 1012
`
`Ingemar J. Cox et al., “Review of Watermarking and the Importance
`of Perceptual Modeling,” in Proceedings of SPIE, vol. 3016, pp. 92-
`99 (June 1997) (“Cox-1997”)
`
`Ex. 1013 Mitchell D. Swanson et al., “Robust Audio Watermarking Using
`Perceptual Masking,” in Signal Processing, vol. 66, no. 3, pp. 337-
`355 (May 1998) (“Swanson”)
`
`- iii -
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`

`

`Ex. 1014  U.S. Patent No. 3,845,391
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
`
`Ex. 1015  U.S. Patent No. 4,931,871
`
`Ex. 1016  U.S. Patent No. 3,004,104
`
`Ex. 1017  U.S. Patent No. 5,629,739
`
`Ex. 1018  U.S. Patent No. 5,745,604 (“’604 Patent”)
`
`Ex. 1019  U.S. Patent No. 5,579,124
`
`Ex. 1020 
`
`Ingemar J. Cox et al., “Secure Spread Spectrum Watermarking for
`Multimedia,” in NEC Research Institute Technical Report 95-10, pp.
`1-33 (1995) (“Cox-1995”)
`
`Ex. 1021  Chung-Ping Wu et al., “Robust and efficient digital audio
`watermarking using audio content analysis,” in Proceedings of SPIE,
`Vol. 3971, pp. 382-392 (2000) (“Wu”) (from pages 16-26 of the
`Rachel J. Watters Declaration, Ex. 1053)
`
`Ex. 1022  U.S. Patent No. 6,151,578
`
`Ex. 1023  Qiang Cheng et al., “Spread Spectrum Signaling for Speech
`Watermarking,” in Proceedings of 2001 IEEE International
`Conference on Acoustics, Speech, and Signal Processing, vol. 3, pp.
`1337-1340 (2001) (from pages 12-15 of the Rachel J. Watters
`Declaration, Ex. 1054)
`
`Ex. 1024  U.S. Patent No. 7,133,534
`
`Ex. 1025  Declaration of Dr. Mary K. Bolin
`
`Ex. 1026  Declaration of Gordon MacPherson Relating to Ex. 1008
`
`Ex. 1027  U.S. Patent No. 6,996,521
`
`Ex. 1028 
`
`Jean-Claude Risset, “Exploration of Timbre by Analysis and
`Synthesis,” in The Psychology of Music, pp. 113-169 (2nd ed. 1999)
`
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`

`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
`
`Ex. 1029  Hideo Suzuki et al., “On the Perception of Phase Distortion,” in
`Journal of the Audio Engineering Society, vol. 28, no. 9, pp. 570-574
`(1980)
`
`Ex. 1030  Declaration of Ziaad Khan Relating to Ex. 1008
`
`Ex. 1031  Stanley P. Lipshitz, “On the Audibility of Midrange Phase Distortion
`in Audio Systems,” in Journal of the Audio Engineering Society, vol.
`30, no. 9, pp. 580-595 (Sept. 1982)
`
`Ex. 1032  Wen-Nung Lie et al., “Robust and High-Quality Time-Domain
`Audio Watermarking Subject to Psychoacoustic Masking,” in 2001
`IEEE International Symposium on Circuits and Systems, vol. 2, pp.
`45-48 (2001) (“Lie”)
`
`Ex. 1033  Kaliappan Gopalan et al., “Data Embedding in Audio Signals,” in
`2001 IEEE Aerospace Conference Proceedings, vol. 6, pp. 2713-
`2720 (2001)
`
`Ex. 1034  Declaration of Rachel J. Watters Relating to Exhibit 1011
`
`Ex. 1035  Alessandro Piva et al., “Managing Copyright in Open Networks,” in
`IEEE Internet Computing, vol. 6, no. 3, pp. 18-26 (2002)
`
`Ex. 1036  Reserved- Not Used
`
`Ex. 1037  U.S. Patent Application Publication 2003/0028381
`
`Ex. 1038  U.S. Patent Application Publication 2003/0076245
`
`Ex. 1039 
`
`Ingemar Cox et al., “The First 50 Years of Electronic
`Watermarking,” in EURASIP Journal on Advances in Signal
`Processing, pp. 126-132 (2002)
`
`Ex. 1040  Changsheng Xu et al., “Content-Based Digital Watermarking for
`Compressed Audio,” in RIAO2000: Content-Based Multimedia
`Information Access, vol. 1, pp. 390-402 (2000)
`
`Ex. 1041 
`
`Jaap Haitsma et al., “Audio Watermarking for Monitoring and Copy
`Protection,” in ACM Multimedia Workshop, pp. 119-122 (2000)
`
`Ex. 1042  U.S. Patent No. 6,633,653 (“Hobson”)
`
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`

`

`Ex. 1043  U.S. Patent No. 6,298,322
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`Ex. 1044  U.S. Patent No. 5,450,490 (“Jensen”)
`
`Ex. 1045  U.S. Patent No. 6,175,627 (“Petrovic”)
`
`Ex. 1046 
`
`Ingemar Cox et al., “Some General Methods for Tampering with
`Watermarks,” in IEEE Journal on Selected Areas in
`Communications, vol. 16, no. 4, pp. 587-593 (May 1998)
`
`Ex. 1047  U.S. Patent No. 5,949,055
`
`Ex. 1048  U.S. Patent No. 6,101,602
`
`Ex. 1049  U.S. Patent No. 6,064,737
`
`Ex. 1050  U.S. Patent No. 6,141,441
`
`Ex. 1051  Frank Hartung, “Multimedia Watermarking Techniques,” in
`Proceedings of the IEEE, vol. 87, no. 7, pp. 1079-1107 (July 1999)
`
`Ex. 1052  Neil Johnson, “Exploring Steganography: Seeing the Unseen,” in
`Computer, vol. 31, no. 26-34 (Feb. 1998)
`
`Ex. 1053  Declaration of Rachel J. Watters Relating to Exhibit 1021
`
`Ex. 1054  Declaration of Rachel J. Watters Relating to Exhibit 1023
`
`Ex. 1055 
`
`Ingemar J. Cox et al., “Secure Spread Spectrum Watermarking for
`Multimedia,” in IEEE Transactions on Image Processing, vol. 6, no.
`12, pp. 1673-1687 (Dec. 1997) (“Cox-SSSW”)
`
`Ex. 1056  Declaration of Gordon MacPherson Relating to Exhibit 1055
`
`Ex. 1057 
`
`Sotera Stipulation to be filed on September 23, 2022 in the U.S.
`District Court for the Central District of California
`
`
`
`
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`- vi -
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`

`

`I.
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
`
`INTRODUCTION
`Patent Owner’s Response (Paper 27, “POR”) largely mirrors the same
`
`rejected assertions in Patent Owner’s Preliminary Response. None of Patent
`
`Owner’s assertions are supported by an expert declaration or by any other
`
`corroborating evidence—they are merely attorney statements that often
`
`mischaracterize or miscomprehend Petitioner’s positions, the teachings of prior art
`
`and the ’961 patent and its claims. Patent Owner’s arguments regarding the
`
`Petition’s motivations to combine mischaracterize the Petition’s reasoning and
`
`wholly fail to address motivations to combine related to the tradeoffs between
`
`security, robustness and audibility of embedded watermarks. Similarly, Patent
`
`Owner’s arguments regarding the incompatibility of some references rely on
`
`mischaracterizing the prior art or inventing non-existent claim limitations.
`
`Ultimately, Patent Owner’s arguments should fail for the same reasons the Board
`
`found them unconvincing in the Institution Decision. (Paper 12, “Inst. Dec.”).
`
` For the reasons described herein and in the Petition, the Board should find
`
`the challenged claims obvious.
`
`II.
`
`PATENT OWNER FAILS TO ADDRESS THE BENEFITS GAINED
`BY THE PROPOSED COMBINATION
`Petitioner presents multiple reasons for the proposed modification of
`
`Srinivasan (Ex. 1005) with Cabot (Ex. 1006) and Kudumakis (Ex. 1007), including
`
`improved security and robustness. As explained in Kudumakis, the fundamental
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`frequency and its harmonics change unpredictably throughout the audio signal
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`(Pet. 24; Kudumakis, 5:3-16, 3:17-18, 4:26-28.), which made the removal or
`
`alteration of the watermark more difficult for an attacker. The combination also
`
`improves robustness by embedding watermarks in perceptually more significant
`
`lower frequencies that are less susceptible to common signal distortions and
`
`malicious attacks. (Pet. 24, citing Cox (Ex. 1020); Scordilis, ¶ 128). For example,
`
`embedding a watermark in the 4.8-6kHz range, as suggested by Srinivasan, could
`
`make it vulnerable to common signal distortions, such as additive noise, and
`
`attacks, such as low-pass filtering. (Pet. 25, citing Wu (Ex. 1021); Scordilis, ¶
`
`129.) Additionally, embedding in a lower range of frequencies would expand the
`
`use of watermarks in telephony and video conferencing applications that
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`proliferated in the early 2000s, which had spectrum less than about 3800Hz. (Pet.
`
`26; Scordilis, ¶ 132).
`
`The multiple benefits gained by selecting the fundamental and its overtone
`
`(third harmonic) spanning lower frequency ranges would have motivated a POSA
`
`to implement the proposed combination.
`
`Patent Owner fails to address any of the above noted reasons for this
`
`combination.
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
`III. PATENT OWNER’S ARGUMENTS AGAINST THE SRINIVASAN-
`CABOT-KUDUMAKIS COMBINATION ARE CONTRADICTED BY
`THE EVIDENCE OF RECORD
`Patent Owner’s main argument against the Srinivasan-Cabot-Kudumakis
`
`combination purports (without any corroborating evidence) that “[t]o use a
`
`fundamental and third harmonic, the frequency range would have to be lowered,
`
`bringing it to within the more sensitive range of human hearing, which contradicts
`
`what Srinivasan teaches.” (POR, 40.) Patent Owner is wrong for several reasons.
`
`A.
`Srinivasan does not mandate using 4.8-6kHz range
`Srinivasan explains: “code frequencies fi used for coding a block may be
`
`chosen from the Fourier Transform ℑ{v(t)} at a step 46 in the 4.8 kHz to 6 kHz
`
`range in order to exploit the higher auditory threshold in this band.”1
`
`(Srinivasan, 7:64-8:5; Pet. 12.) Contrary to Patent Owner’s position, Srinivasan
`
`does not mandate the use of 4.8-6kHz frequency band, as evident by the use of
`
`permissive language (“may”) in the above excerpt. This is further corroborated by
`
`Srinivasan’s Figure 2 (annotated in the Petition and reproduced below), where step
`
`46 states “select frequencies f1 and f0 for modulation,” without requiring a specific
`
`frequency range. (Pet. 32-33.)
`
`
`1 All bold-italic emphasis added by Petitioner, unless otherwise specified.
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`

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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`
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`B.
`Srinivasan does not require absolute inaudibility
`Contrary to Patent Owner’s assertions (POR, 42), Srinivasan’s watermarks
`
`are not inaudible, as evident by Srinivasan’s explanations of different phase
`
`embedding alternatives: one that forced the differential phase of the frequency
`
`components to be at 0 or 180 degrees, “which could make the code audible,” and
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`another that reduced audibility by using a phase neighborhood of ± 45 degrees.
`
`(Srinivasan, 11:26-54; Pet. 34-35.) Thus, Srinivasan recognized different
`
`embedding techniques (within the scope of its invention) could produce different
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`levels of audibility.
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`Even Patent Owner, among many contradicting statements, appears to admit
`
`absolute inaudibility is not mandated by Srinivasan by stating: “Srinivasan
`
`addresses low visibility by selecting an operating frequency range in which the
`
`human ear is less sensitive.” (POR, 40; Srinivasan, 11:12-14: “This encoding
`
`approach results in a lower audibility level.”) In fact, it was well known that low
`
`imperceptibly was one of several goals of a watermarking system, but it was also
`
`well known that audibility could be traded off for robustness or security, as
`
`explained by Dr. Scordilis and numerous supporting references (Scordilis, ¶¶ 103-
`
`116), and as corroborated by Srinivasan’s alternative phase embedding techniques.
`
`(Srinivasan, 11:26-54; Pet. 34-35.)
`
`C. The combinations in Grounds 1 and 2 maintain low audibility
`A POSA would have understood that watermarks embedded in the proposed
`
`combination would have maintained a low audibility. (Pet. 22-23.) Notably,
`
`Srinivasan, in suggesting the 4.8-6kHz band, did not consider selecting a
`
`fundamental and its harmonics for embedding the watermarks, but a POSA would
`
`have understood from Cabot that there was an alternative way to achieve low-
`
`visibility differential phase encoding by modifying the phase of the third harmonic
`
`relative to the fundamental. (Pet. 22.) Such an alternative would have allowed
`
`embedding of watermarks with low audibility using frequency bands lower than
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`

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`4.8-6kHz. (Pet. 22-23.)
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`As explained further below, Patent Owner’s assertions that Cabot’s
`
`experiments contradicted having low audibility are incorrect.
`
`D.
`
`Patent Owner ignores Cabot’s explanations and conclusions that
`phase shifts are very hard to detect
`Several of Patent Owner’s assertions are based on mischaracterization of
`
`
`
`Cabot. For example, Patent Owner states “Cabot’s experimental data and
`
`conclusions demonstrate that the phase shifts between fundamental and third
`
`harmonics are audible.” (POR, 42.) But Patent Owner fails to address Cabot’s and
`
`Petitioner’s explanations that (1) Cabot’s controlled experiments were conducted
`
`under pristine laboratory conditions, where (2) the listener wore headphones to
`
`block all other noises, (3) the listener could listen to both the original (unchanged)
`
`and modified audio signals to detect any differences, (4) the listener was
`
`familiarized with the sound of the difference ahead of time, was given control to
`
`switch between the original and modified signals and to listen for as long as they
`
`liked before making their determination, (5) the audio content only included the
`
`fundamental and third harmonic that were isolated from all other sounds that might
`
`mask the phase change, and (6) subjects tested before this initial step was
`
`introduced “refused to believe that there was a difference.” (Cabot, 570-571; Pet.
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`15-18, 22; Ex. 2011, 14:17-15:13.)
`
`Patent Owner also ignores Cabot’s statements that (A) the audibility of
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`

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`phase shifts in harmonically related tones had been studied “for many years” and
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`were reported to be inaudible (Cabot, 568; Pet. 15), (B) Cabot’s results “correlate
`
`well with those of previous researchers” (Cabot, 571; Pet. 18) and (C) Cabot’s
`
`conclusion that “although differences were detectable, they were subtle. This raises
`
`the question of its audibility compared to the more familiar forms of distortion.”
`
`(Cabot, 571; Pet. 22-23). Importantly, Patent Owner fails to respond to
`
`Petitioner’s and Dr. Scordilis’s explanations that such subtle differences would not
`
`be noticeable “under real-world conditions where the listener is unaware of the
`
`phase shift and the audio signal has other sounds masking the phase shift.” (Pet.
`
`23; Scordilis, ¶¶ 121-124; see also Ex. 2011, 18:1-9: “If we are talking about a
`
`useful signal such as listening to music, listening to a lecture, listening to speech,
`
`through headphones, loud speakers, et cetera, you know, like in our everyday life,
`
`then a phase change [] and … on top of that, we don't have access to the unaltered
`
`original version, if that ever exists, then that would be impossible or almost
`
`impossible to detect any phase issues or changes in what a listener is presented.”)
`
`These conclusions were also corroborated by other references such as Risset.
`
`As Dr. Scordilis explains:
`
`“Risset … states that although changing the phase between the
`harmonics of a periodic tone can alter the timbre of audio under
`certain conditions, “this effect is quite weak, and it is generally
`inaudible in a normally reverberant room where phase relations are
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`smeared. Ex. 1028, 114. Risset further observes that ‘this remarkable
`insensitivity to phase…holds only for the phase relationship between
`the harmonics of periodic tones.’ See id.”
`
`(Scordilis, ¶ 122, citing Risset.)
`
`Therefore, a POSA would have understood that selection of the fundamental
`
`and third harmonic for implementing a phase change, as taught by Cabot, would
`
`have produced watermarks that were not audible in any practical scenario, and
`
`would have produced only subtle changes for some larger phase shifts detectable in
`
`a laboratory setting by trained listeners. (Pet. 18, citing Cabot: “For the
`
`frequencies and level used, the ear is incapable of detecting less than about 15º of
`
`phase shift”). Some larger phase shifts were detectable but “subtle.” Id., 570-571
`
`(Observations & Discussions at ¶ 4, Conclusions).”2
`
`E.
`
`The ’961 patent’s claims do not recite any limitations related to a
`particular audibility level
`The challenged claims do not recite any limitations that impose a particular
`
`audibility requirement of the embedded watermarks. As Dr. Scordilis explains,
`
`
`2 See also Dr. Scordilis’s deposition transcript, Ex. 2011, 19:7-12: “Also, in … my
`
`personal research activity, my research activity throughout my personal life and
`
`my publications, et cetera, in several of them I make the same statement, that phase
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`change is extremely hard to detect if not impossible to detect.”
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`“the acceptable degree of audibility of an embedded code may vary with
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`application, for example with a high-quality music reproduction being able to
`
`tolerate less audibility of the code than a less sophisticated musical recording.
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`Factors such as the listening environment, equipment characteristics, and listener
`
`characteristics may impact the acceptable degree of audibility.” (Scordilis, ¶ 123.)
`
`The ’961 patent admitted the tradeoffs between audibility (visibility),
`
`robustness and data capacity, which were already known by a POSA. (Ex. 1001,
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`2:3-15; see also Scordilis, ¶¶ 103-116, describing numerous references that
`
`recognized these tradeoffs.). The applicant during the prosecution of the ’961
`
`patent could have presented claims that imposed audibility requirements but,
`
`instead, opted to pursue broad claims that say nothing about audibility, let alone
`
`imposing an absolute inaudibility criteria. Notably, Patent Owner seems to suggest
`
`that any watermarking technique that produces an iota of audibility (even if
`
`detectable only under rigorous laboratory testing by trained listeners) cannot be
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`combined with Srinivasan because it would “teach away from the techniques of the
`
`’961 patent.” (POR, 1.)
`
`This assertion contradicts the ’961 patent’s description, which explains that
`
`its phase embedding method produces artifacts (Ex. 1001, 7:53-56: “[a]n artifact
`
`of the phase manipulation method described above is a small discontinuity at the
`
`frame boundaries.”). The ’961 patent further proposes three different
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`modifications to its basic phase embedding technique to mitigate those artifacts.
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`(Ex. 1001, 7:56-8:24). However, none of those additional mitigating techniques
`
`are part of the ’961 claims.
`
`
`
`As the Board recognized, Patent Owner’s teaching away arguments are of
`
`questionable relevance because they do not “relate to and are” not “commensurate
`
`in scope with the ultimate claims at issue.” See Idemitsu Kosan Co., Ltd., v. SFC
`
`Co., Ltd., 870 F.3d 1376, 1381 (Fed. Cir. 2017) (“Idemitsu’s teaching away
`
`argument is of questionable relevance anyway. Evidence concerning whether the
`
`prior art teaches away from a given invention must relate to and be commensurate
`
`in scope with the ultimate claims at issue.” (Inst. Dec. 40-41).
`
`Here, Patent Owner’s teaching away arguments based on a phantom
`
`inaudibility requirement is not commensurate in any way with the scope of the
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`claims or the teachings of the ’961 patent.
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`F.
`The combination does not need to produce an optimum system
`Even if, arguendo, the proposed combination produced some subtle audible
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`
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`artifacts (an assertion that is not correct, and is not corroborated by any supporting
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`evidence), it would not undermine a finding of obviousness. Notably, obviousness
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`does not require a perfect system as made clear by the Federal Circuit. (See Intel
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`Corp. v. PACT XPP Schweiz AG, 61 F.4th 1373, 1380 (Fed. Cir. 2023): “[i]t’s not
`
`necessary to show that a combination is the best option, only that it be a suitable
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`option.” See also Allied Erecting and Dismantling Co. v. Genesis Attachments,
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
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`LLC, 825 F.3d 1373, 1381 (Fed. Cir. 2016) (“A given course of action often has
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`simultaneous advantages and disadvantages, and this does not necessarily obviate
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`motivation to combine.”)) As noted earlier, any purported subtle increase in
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`audibility in the proposed system compared to Srinivasan would have been
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`counterbalanced by improvements gained in security and robustness, as well as
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`expanded use in low-band audio applications. (See Section II, supra).
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`IV. KUDUMAKIS DOES NOT TEACH AWAY FROM THE PROPOSED
`COMBINATION
`Patent Owner misinterprets the combination by stating that Kudumakis
`
`teaches away from embedding at strong points. (POR, 43-47.) This assertion
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`incorrectly assumes that the proposed combination advocates changing the phase
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`of the fundamental tone or using Kudumakis’s notch embedding. Both (all)
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`assumptions are incorrect. As the Petition explained:
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`Kudumakis’s notch encoding technique uses the fundamental
`and its harmonics to determine where to insert the codes, and
`the codes are placed at their “edges” because with notch
`encoding the “codes are more perceptible if the notch
`frequencies coincide with the main frequency components of
`the signal.” Kudumakis, 3:4-9, 4:26-5:2; Scordilis, ¶ 136. Since
`Srinivasan uses differential phase encoding instead of notch
`encoding, a POSA would have understood it was unnecessary
`for inaudibility to place the codes at the “edges” of the
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
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`fundamental and its harmonics. Scordilis, ¶ 136.
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`(Pet. at 27-28.)
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`Notably, the combination proposes using the differential phase encoding
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`technique of Srinivasan, using the fundamental and the third harmonic as f0 and f1,
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`and changing the phase of the third harmonic as explained in Cabot. (Pet. 36:
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`“Thus, the Srinivasan/Cabot/Kudumakis Combination quantizes a phase difference
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`of at least one overtone (third harmonic) relative to the fundamental tone to
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`embed at least one bit of the data to be embedded as claimed.”).
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`The Petition further elaborated that Kudumakis described using phase
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`modulation (Pet. 20; Kudumakis, 6:1-2; Scordilis, ¶ 88), and techniques for
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`identifying the fundamental and its harmonics using algorithms such as FFT,
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`Cepstrum, and Correlogram. (Pet. 20, 27; Kudumakis, 4:26-30, Scordilis ¶¶ 88,
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`134). Kudumakis also provided further motivation for using locations of harmonic
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`and fundamentals to enhance security against malicious attacks since those
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`locations changed unpredictably throughout the audio signal. (Pet. 24; Kudumakis,
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`5:3-16, 3:17-18; Scordilis, ¶ 127.)
`
`V. HOBSON IS ANALOGOUS ART
`Patent Owner asserts that Hobson is non-analogous art because it describes
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`watermarking techniques for digital images as opposed to audio signals. (POR,
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`50-51.) Patent Owner’s assertions fall considerably short of satisfying the
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`requirements for non-analogous art.
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
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`Two separate tests define the scope of analogous art: (1) whether the art is
`
`from the same field of endeavor, regardless of the problem addressed and, (2) if the
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`reference is not within the field of the inventor’s endeavor, whether the reference
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`still is reasonably pertinent to the particular problem with which the inventor is
`
`involved. In re Klein, 647 F.3d 1343, 1348 (Fed. Cir. 2011). “A reference is
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`reasonably pertinent if … it is one which, because of the matter with which it
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`deals, logically would have commended itself to an inventor's attention in
`
`considering his problem.” In re Clay, 966 F.2d 656, 659 (Fed. Cir. 1992).
`
`A. Hobson is from the same field of endeavor
`Both Hobson and the ’961 patent relate to watermark embedding methods
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`for digital media. (Hobson, 5-7; Ex. 1001, 4:35-37, 9:10-11.) The claims of the
`
`’961 patent recite embedding in an audio signal, whereas Hobson describes
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`embedding watermarks in images, but both describe phase embedding operations
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`for adding watermarks to a digital content, and more specifically, both describe
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`embedding watermarks by changing the phase of a frequency component.
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`(Hobson, 2:16-23; Ex. 1001, 5:55-6:21, 9:12-20; see also, Ex. 1001, 1:20-24 and
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`Hobson, 2:17-23.)
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`The significant relationship between audio and image watermarking is
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`evident from the description of the ’961 patent itself, which explains digital
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
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`watermarking techniques can be used for images (Ex. 1001, 1:49-52: “…a message
`
`can be embedded in a bitmap image…. In each byte of the bitmap image, the least
`
`significant bit is discarded and replaced by a bit of the message to be hidden.”)
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`Notably, the ’961 patent admits that image watermarking is related to its invention
`
`by describing image watermarking techniques in the section titled
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`“DESCRIPTION OF RELATED ART,” and, additionally, by referring to
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`perceptibility of watermarks as “visibility” (as opposed to audibility). (Ex. 1001,
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`2:3-15, FIG. 1.)
`
`The fact that image and audio watermarking entail many related and
`
`overlapping concepts would have been readily understood by a POSA, as
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`expressed by the following excerpt of Podlichuk:
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`Just as in image and video watermarking, the use of perceptual models
`is an important component in generating an effective and acceptable
`watermarking scheme for audio … Many of the requirements for
`audio watermarking are similar to image watermarking, such as
`imperceptibility (inaudibility), robustness to signal alterations such as
`compression, filtering and A/D and D/A conversion.
`
`(Ex. 1011, page 10 of 16, (Audio Watermarking).)
`
`Cox also recognized that watermarking techniques can be applied to audio,
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`image and video data for the same purpose of providing copyright protection:
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`There has been significant recent interest in watermarking. This is
`primarily motivated by a need to provide copyright protection to
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`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
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`digital content, such as audio, images and video.
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`(Ex. 1012, page 92, (Introduction).)
`
`Tilki, which primarily involved audio watermarking, also included
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`explanations that hidden data can be added to both audio and images:
`
`The ability to add extra hidden information to a signal could be useful
`in many applications. Audio compact discs could be modified to
`contain artist information, song titles, song lyrics, karaoke
`information, still images, and perhaps even video clips.
`
`(Tilki, page 331 (Introduction).)
`
`Therefore, Hobson and the ’961 patent both relate to watermark embedding
`
`techniques for digital media, both describe using phase encoding for embedding
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`watermarks, and are in the same field of endeavor.
`
`B. Hobson is reasonably pertinent to the problem solved in the ’961
`patent
`Patent Owner purports the ’961 patent’s objective was to improve
`
`watermark robustness. (POR, 55-56). That is precisely what the relied upon
`
`sections of Hobson advocated. Notably, Hobson described embedding in multiple
`
`locations to improve robustness (recoverability) of the watermarks. (Pet. 51,
`
`Hobson, 3:49-57.) That is, by embedding in multiple locations, Hobson improved
`
`the chances of detecting a watermark (e.g., via averaging) even if some of the
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`watermarks could not be recovered. (Id.) Therefore, Hobson strived to improve
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`the watermarking robustness and is reasonably pertinent to the same problem that
`
`PTAB Case No. IPR2022-01544, Patent No. 7,289,961 B2
`Petitioner's Reply to Patent Owner’s Response
`
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`the ‘961 is purported to address.
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`Additionally, Patent Owner, mischaracterizes both Hobson and the ’961
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`patent by stating: “Hobson involves fragile watermarking whereby a signal is
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`embedded that is designe