Trials@uspto.gov
`571-272-7822
`
`Paper 12
`Date: April 21, 2023
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`SONY GROUP CORP. (JAPAN), SONY CORP. OF AMERICA, SONY
`INTERACTIVE ENTERTAINMENT LLC, SONY PICTURES
`ENTERTAINMENT INC., SONY ELECTRONICS INC.,
`and VERANCE CORP.,
`Petitioner,
`v.
`MZ AUDIO SCIENCES, LLC,
`Patent Owner.
`
`IPR2022-01544
`Patent 7,289,961 B2
`
`
`
`
`
`
`
`
`
`Before KARL D. EASTHOM, DAVID C. MCKONE, and
`IFTIKHAR AHMED, Administrative Patent Judges.
`Opinion for the Board filed by Administrative Patent Judge EASTHOM.
`
`Opinion Dissenting filed by Administrative Patent Judge MCKONE.
`
`EASTHOM, Administrative Patent Judge.
`
`
`
`
`DECISION
`Granting Institution of Inter Partes Review
`35 U.S.C. § 314
`
`
`
`

`

`IPR2022-01544
`Patent 7,289,961 B2
`
`Sony Group Corp. (Japan), Sony Corp. of America, Sony Interactive
`Entertainment LLC, Sony Pictures Entertainment Inc., Sony Electronics Inc.,
`and Verance Corp. (collectively “Petitioner”) filed a Petition requesting inter
`partes review of claims 1–10 of U.S. Patent No. 7,289,961 B2 (Ex. 1001,
`“the ’961 patent”). Paper 7 (“Pet.”).1 MZ Audio Sciences, LLC (“Patent
`Owner”) timely filed a Preliminary Response. Paper 11 (“Prelim. Resp.”).
`We have authority to determine whether to institute an inter partes
`review. See 35 U.S.C. § 314 (2018); 37 C.F.R. § 42.4(a) (2020). Institution
`of an inter partes review requires that “the information presented in the
`petition and . . . any response . . . shows that there is a reasonable likelihood
`that the petitioner would prevail with respect to at least 1 of the claims
`challenged in the petition.” 35 U.S.C. § 314(a). For the reasons set forth
`below, we determine that there is a reasonable likelihood that Petitioner will
`prevail with respect to at least one challenged claim. Accordingly, we
`institute an inter partes review of the ’961 patent.
`
`I. BACKGROUND
`A. Related Matters
`The parties indicate that Patent Owner asserted the ’961 patent in
`district court lawsuits, including MZ Audio Sciences, LLC v. Sony Group
`Corp. (Japan), No. 1:21-cv-0166 (D. Del.), and MZ Audio Sciences, LLC v.
`Sony Group Corp. (Japan), 2:22-cv-00866 (C.D. Cal.). Pet. xi; Paper 9, 1.
`The parties identify no other related proceedings.
`
`
`1 The Petition also identifies Sony Interactive Entertainment Inc. and Sony
`DADC US Inc. as real parties in interest and states “other Sony affiliates
`could be real parties in interest.” Pet. xi.
`
`2
`
`

`

`IPR2022-01544
`Patent 7,289,961 B2
`
`B. The Asserted Grounds
`Petitioner asserts the following grounds of unpatentability (Pet. 2):
`
`Claim(s) Challenged 35 U.S.C.2 §
`1–10
`103(a)
`
`Reference(s)/Basis
`Srinivasan3, Cabot4, Kudumakis5
`
`2, 3, 5, 7, 8, 10
`
`1–10
`
`103(a)
`
`103(a)
`
`Srinivasan, Cabot, Kudumakis,
`Hobson6
`
`Kudumakis, Tilki7, Cabot
`
`In support, Petitioner relies on the testimony of Dr. Michael Scordilis
`(Ex. 1003).
`
`
`2 The Leahy-Smith America Invents Act, Pub. L. No. 112-29, 125 Stat. 284
`(2011) (“AIA”), amended 35 U.S.C. § 103 (effective Mar. 16, 2013).
`Petitioner points out that “[t]he application from which U.S. Patent No.
`7,289,961 issued claims priority to U.S. Provisional Application No.
`60/479,438, filed June 19, 2003.” Pet. xi. Because the earliest possible
`effective filing date for the ’961 patent precedes the effective date of the
`applicable AIA amendment, the pre-AIA version of § 103 applies.
`3 Srinivasan, US 6,272,176 B1, issued Aug. 7, 2001. Ex. 1005.
`4 R. C. Cabot et al., Detection of Phase Shifts in Harmonically Related
`Tones, J. AUDIO ENG. SOC., VOL. 24, NO. 7 (Sept. 1976). Ex. 1006.
`5 Kudumakis et al., Int. Pub. WO 01/58063, published Aug. 9, 2001.
`Ex. 1007.
`6 Hobson et al., US 6,633,653 B1, issued Oct. 14, 2003, filed Feb. 4, 2000.
`Ex. 1042.
`7 J.F. Tilki et al., Encoding a Hidden Auxiliary Channel onto a Digital Audio
`Signal Using Psychoacoustic Masking, PROCEEDINGS IEEE
`SOUTHEASTCON ’97, “Engineering the New Century,” Apr. 12–14, 1997.
`Ex. 1008; see also Pet. 52–53 (arguing that Tilki is prior art under
`§§ 102(a)–(b)) (citing Ex. 1025, 1–8; Ex. 1026, 1–2; Ex. 1027, 2; Ex. 1030,
`1–2; Ex. 1032, 48; Ex. 1033, 2719).
`
`3
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`

`IPR2022-01544
`Patent 7,289,961 B2
`
`C. The ’961 Patent
`The ’961 patent relates to embedding data in an audio signal for
`watermarking, steganography, or other purposes. Ex. 1001, code (57). The
`process divides the audio signal into time frames that contain frequency
`bands representing the audio signal. Id. Then, “the relative phases of one or
`more frequency bands are shifted to represent the data to be embedded.” Id.
`
`D. Challenged Claims
`Petitioner challenges all ten claims of the ’961 patent. Of these,
`claims 1, 4, 6, and 9 are independent. For purposes of this Institution
`Decision, claim 1 is representative. Claim 1 follows (information added to
`conform to Petitioner’s nomenclature):
`1.
`[1PRE] A method for embedding data in an audio signal,
`the method comprising:
`
`[1A] (a) dividing the audio signal into a plurality of time
`frames and, in each time frame, a plurality of frequency
`components;
`
`[1B] (b) in each of at least some of the plurality of time
`frames, selecting at least two of the plurality of frequency
`components; and
`
`[1C] (c) altering a phase of at least one of the plurality of
`frequency components in accordance with the data to
`be embedded, wherein:
`
`[1D] step (b) comprises selecting a fundamental tone and
`at least one overtone; and
`
`[1E] step (c) comprises quantizing a phase difference of
`the at least one overtone relative to the fundamental tone to
`embed at least one bit of the data to be embedded.
`II. DISCRETIONARY DENIAL
`Patent Owner contends that we should exercise our discretion under
`35 U.S.C. § 325(d) to deny institution. Prelim. Resp. 63–66.
`
`4
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`

`IPR2022-01544
`Patent 7,289,961 B2
`A. Legal Standard for Exercising Discretion under Section 325(d)
`The Board has discretion to deny a petition. See, e.g., 35 U.S.C.
`
`§ 325(d); Cuozzo Speed Techs., LLC v. Lee, 579 U.S. 261, 273 (2016)
`(“[T]he agency’s decision to deny a petition is a matter committed to the
`Patent Office’s discretion.”). The PTAB’s Trial Practice Guide identifies
`considerations that may warrant exercise of this discretion. Consolidated
`Trial Practice Guide, 55–63 (Nov. 2019) (“Consolidated TPG”).8
`The Board may discretionarily deny institution of an inter partes
`review when a petition presents “the same or substantially the same prior art
`or arguments [that] previously were presented to the Office.” 35 U.S.C.
`§ 325(d); see also 37 C.F.R. § 42.4(a) (the Board institutes trial on behalf of
`the Director). To evaluate whether such a denial is appropriate, the Board
`determines
`(1) whether the same or substantially the same art previously was
`presented to the Office or whether the same or substantially the
`same arguments previously were presented to the Office; and (2)
`if either condition of first part of the framework is satisfied,
`whether the petitioner has demonstrated that the Office erred in
`a manner material to the patentability of challenged claims.
`Advanced Bionics, LLC v. MED-EL Elektromedizinische Geräte GmbH,
`IPR2019-01469, Paper 6 at 8 (PTAB Feb. 13, 2020) (precedential). This
`two-part Advanced Bionics framework involves evaluating the following
`non-exclusive factors:
`(a) the similarities and material differences between the asserted
`art and the prior art involved during examination; (b) the
`cumulative nature of the asserted art and the prior art evaluated
`during examination; (c) the extent to which the asserted art was
`evaluated during examination, including whether the prior art
`was the basis for rejection; (d) the extent of the overlap between
`
`8 Available at https://www.uspto.gov/TrialPracticeGuideConsolidated.
`
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`IPR2022-01544
`Patent 7,289,961 B2
`the arguments made during examination and the manner in which
`petitioner relies on the prior art or patent owner distinguishes the
`prior art; (e) whether petitioner has pointed out sufficiently how
`the examiner erred in its evaluation of the asserted prior art; and
`(f) the extent to which additional evidence and facts presented in
`the petition warrant reconsideration of the prior art or arguments.
`Becton, Dickinson & Co. v. B. Braun Melsungen AG, IPR2017-01586,
`Paper 8 at 17–18 (PTAB Dec. 15, 2017) (precedential as to Section III.C.5,
`first paragraph). Factors (a), (b), and (d) relate to the first part of the
`Advanced Bionics framework (i.e., whether the art or arguments presented in
`the Petition are the same or substantially the same as those previously
`presented to the Office), and factors (c), (e), and (f) relate to the second part
`(i.e., “whether the petitioner has demonstrated a material error by the
`Office” in its prior consideration of the prior art or arguments). Advanced
`Bionics, Paper 6 at 10. If a review of factors (a), (b), and (d) shows that the
`same or substantially the same art or arguments previously were presented to
`the Office, then we analyze factors (c), (e), and (f) to determine whether the
`petitioner demonstrates that the Office erred in a manner material to the
`patentability of the challenged claims. See id. at 9–10.
`
`B. Analysis
`Part 1: Whether the Same or Substantially the Same
`Art or Arguments Were Previously Presented
`Petitioner concedes that during prosecution, “[a] divisional of
`Srinivasan (published Application No. 2002/0034224) was cited but was
`neither applied nor commented on by the Examiner.” Pet. 76 (citing
`Ex. 1002 (prosecution history), 129). However, Petitioner contends that
`“[t]he Office lacked expert testimony regarding Srinivasan and did not
`consider Srinivasan in combination with the other Ground 1 references.” Id.
`
`6
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`

`IPR2022-01544
`Patent 7,289,961 B2
`(emphasis added). Therefore, Petitioner asserts that “[d]iscretionary denial
`is not appropriate.” Id.
`In other words, Petitioner appears to agree that with respect to
`Ground 1, Srinivasan (Ex. 1005) is cumulative to the Srinivasan publication
`(i.e., published Application No. 2002/0034224) cited by the Examiner
`during prosecution. See Ex. 1002, 129; Regeneron Pharm., Inc. v. Merus
`N.V., 864 F.3d 1343, 1350 (Fed. Cir. 2017) (“A reference is cumulative
`when it ‘teaches no more than what a reasonable examiner would consider to
`be taught by the prior art already before the PTO.’” (citation omitted)).
` On the other hand, as Petitioner indicates, the Examiner did not
`consider any other references the Petition employs in Ground 1, namely,
`Kudumakis and Cannon. See Pet. 76. In addition, the Examiner only
`considered Srinivasan (published Application No. 2002/0034224) and did
`not consider the other three references the Petitioner employs in Ground 2,
`namely, Cabot, Kudumakis, Hobson. See Ex. 1002. And finally, the
`Examiner did not consider any of the references the Petition employs in
`Ground 3, namely, Kudumakis, Tilki, and Cabot. See id.
`Patent Owner “respectfully requests that the Board decline to institute
`on Grounds 1–2 under § 325(d).” Prelim. Resp. 66. Patent Owner bases this
`request on Petitioner’s “admi[ssion]” that the Examiner previously cited and
`considered Srinivasan (published Application No. 2002/0034224). See id. at
`63–65.
`
`Because the Examiner did not consider the specific combination of
`references asserted in the three grounds during prosecution and because
`those three grounds cover all the challenged claims, we find that the same or
`substantially the same art or argument was not presented to the Office.
`
`7
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`IPR2022-01544
`Patent 7,289,961 B2
`Therefore, the first part of the framework in Advanced Bionics is not
`satisfied.
`For the reasons above, we find that the same or substantially the same
`art was not presented to the Office under Part 1 of the Advanced Bionics
`framework. Accordingly, we do not exercise discretion to deny institution
`under § 325(d).
`
`III. ANALYSIS
`A. Legal Standards
`“In an [inter partes review], the petitioner has the burden from the
`onset to show with particularity why the patent it challenges is
`unpatentable.” Harmonic Inc. v. Avid Tech., Inc., 815 F.3d 1356, 1363 (Fed.
`Cir. 2016) (citing 35 U.S.C. § 312(a)(3) (requiring inter partes review
`petitions to identify “with particularity . . . the evidence that supports the
`grounds for the challenge to each claim”)). This burden of persuasion never
`shifts to the patent owner. Dynamic Drinkware, LLC v. Nat’l Graphics, Inc.,
`800 F.3d 1375, 1378 (Fed. Cir. 2015).
`The legal question of obviousness is resolved on the basis of
`underlying factual determinations including (1) the scope and content of the
`prior art; (2) any differences between the claimed subject matter and the
`prior art; (3) the level of ordinary skill in the art; and (4) when in evidence,
`objective evidence of nonobviousness. Graham v. John Deere Co. of Kan.
`City, 383 U.S. 1, 17–18 (1966). One seeking to establish obviousness based
`on more than one reference also must articulate sufficient reasoning with
`rational underpinnings to combine teachings. See KSR Int’l Co. v. Teleflex
`Inc., 550 U.S. 398, 418 (2007).
`
`8
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`

`IPR2022-01544
`Patent 7,289,961 B2
`B. Level of Ordinary Skill in the Art and Dr. Scordilis’s Testimony
`Level of Ordinary Skill
`Petitioner asserts that a person of ordinary skill in the art “would have
`had a bachelor’s degree in electrical engineering or a related field with
`coursework in signal processing, plus two years of academic and/or industry
`experience in signal processing or a related field. More education could
`substitute for experience, and vice versa.” Pet. 7. At this stage, “Patent
`Owner does not dispute Petitioners’ definition of a [person of ordinary skill
`in the art].” Prelim. Resp. 2.
`Based on a review of the preliminary record, for purposes of the
`Institution Decision, we adopt Petitioner’s proposed level of ordinary skill in
`the art because it is consistent with the evidence of record, including the
`asserted prior art, other references of record, and the ’961 patent
`specification.
`
`Dr. Scordilis’s Testimony
`Patent Owner argues that prior statements by Dr. Scordilis “[c]ast
`
`[d]oubt on [h]is [p]resent [o]pinions.” Prelim. Resp. 40. To support this
`argument, Patent Owner argues that “Dr. Scordilis opines that the phase
`encoding techniques disclosed in the ᾽961 patent are allegedly obvious,
`despite the contrary statement in his own patent, which casts a shadow on
`his opinions.” Id. at 41. To support this argument, Patent Owner quotes
`“the ’521 patent” (Ex. 2008), which lists Dr. Scordilis as an inventor. Id.
`(referring to Iliev et al., US Patent No. 6,996,521 B2, filed Oct. 4, 2001,
`issued Feb. 7, 2006 (Ex. 2008)).9 In particular, Patent Owner quotes the
`
`
`9 See Ex. 2008; Ex. 1002, 118–19 (asserting that the ’521 patent anticipates
`claims during prosecution of the ’961 patent application).
`
`9
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`IPR2022-01544
`Patent 7,289,961 B2
`’521 patent as follows: “While masking in the power spectrum of auditory
`signals dominates audio coding and watermarking techniques, the phase
`information has not been involved to date.” Id. at 40–41 (alteration in
`original) (quoting Ex. 2008, 2:17–24). According to Patent Owner, “[t]his
`statement is strong contemporaneous evidence that those skilled in the art
`were focused on masking in the power spectrum—and not on phase
`encoding—as a means for data encoding/decoding in audio signals.”
`Id. at 41 (arguing that “nearly two decades after the fact, Dr. Scordilis opines
`that the phase encoding techniques disclosed in the ᾽961 patent are allegedly
`obvious, despite the contrary statement in his own patent, which casts a
`shadow on his opinions”).
`
`This line of argument is unavailing. Patent Owner notes that
` “the ’521 patent formed the basis of prior art objections [sic: rejections]
`during prosecution.” Prelim. Resp. 41 n. 3 (citing Ex. 1002, 85, 118). In
`particular, during prosecution, the Examiner asserted in an anticipation
`rejection that the ’521 patent discloses the claim limitation of “altering a
`phase of at least one of the plurality of frequency components in accordance
`with the data to be embedded,” (Ex. 1002, 119), because the ’521 patent
`discloses an “FFT [(Fast Fourier Transform)] algorithm provided the phase
`value of each component” (id. (quoting Ex. 2008, 5:33–39)), and also
`describes “encoding a single-bit-per-frequency component” “to alter the
`phase of the left channel” (id. (quoting Ex. 2008, 6:48–64)). Therefore,
`contrary to Patent Owner’s arguments, as described by the Examiner during
`prosecution, the ’521 patent does not undermine Dr. Scordilis’s testimony
`here, because the ’521 patent provides further evidence that the technique of
`phase modulating frequency components for embedding data in an audio
`
`10
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`IPR2022-01544
`Patent 7,289,961 B2
`signal was known before the effective date of the ’961 patent. See id., 118–
`119.
`
`Patent Owner also argues that “[w]hile Dr. Scordilis states that he
`assumed ‘the perspective of a person having ordinary skill in the art,’ he
`fails to explain how he did so given his admission that he was ‘a person of
`more than ordinary skill in the art during the relevant timeframe.’” Prelim.
`Resp. 42 (citing Ex. 1003 ¶¶ 18, 39). Contrary to this argument,
`Dr. Scordilis testifies that “[i]n forming my opinions, I have studied and
`considered the materials identified in the list below.” Ex. 1003 ¶ 18. The
`list includes “materials . . . that experts in my field would have reasonably
`relied upon when forming their opinions,” including Exhibits 1001–20,
`1031–33, 1035, 1042–46, 1053. Id. ¶ 19. These references represent the
`level of skill in the art, as determined above. Patent Owner does not allege
`that Dr. Scordilis provides testimony in his Declaration based on the
`perspective as an expert. See id. Experts of relatively higher skill routinely
`provide testimony from the perspective of artisans of ordinary skill.
`Accordingly, this argument does not undermine the testimony of
`Dr. Scordilis on this preliminary record.
`
`Patent Owner also argues that “Petitioners’ expert declaration does
`nothing more than parrot the Petition and, thus, is entitled to no weight.”
`Prelim. Resp. 29 (citing 37 C.F.R. § 42.65(a) (“Expert testimony that does
`not disclose the underlying facts or data on which the opinion is based is
`entitled to little or no weight.”)). Patent Owner’s generic argument without
`specifics does not undermine Petitioner’s showing or provide a sufficient
`reason to discount the weight of Dr. Scordilis’s testimony. Where
`appropriate, Dr. Scordilis routinely cites to record evidence to support his
`
`11
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`IPR2022-01544
`Patent 7,289,961 B2
`testimony and Patent Owner does not argue otherwise. See, e.g., Ex. 1003
`¶¶ 46–137.
`
`C. Claim Construction
`In inter partes reviews, the Board interprets claim language using the
`district-court-type standard, as described in Phillips v. AWH Corp., 415
`F.3d 1303 (Fed. Cir. 2005) (en banc). See 37 C.F.R. § 42.100(b) (2020).
`Under this standard, claim terms have their ordinary and customary
`meaning, as would be understood by a person of ordinary skill in the
`art at the time of the invention, in light of the language of the claims, the
`specification, and the prosecution history. See Phillips, 415
`F.3d at 1313–14.
`Petitioner relies on the plain and ordinary meaning and contends that
`it is unnecessary to construe any claim terms explicitly at this stage. See
`Pet. 8 (citing 37 C.F.R. §42.100(b)). Patent Owner “agrees with Petitioners
`that, for purposes of this Preliminary Response only, all terms of the ᾽961
`patent have their plain and ordinary meaning.” Prelim. Resp. 23.
`As Petitioner contends, it is not necessary to construe any claim terms
`explicitly at this stage. See Nidec Motor Corp. v. Zhongshan Broad Ocean
`Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (stating that “we need only
`construe terms ‘that are in controversy, and only to the extent necessary to
`resolve the controversy’” (quoting Vivid Techs., Inc. v. Am. Sci. & Eng’g,
`Inc., 200 F.3d 795, 803 (Fed. Cir. 1999))).
`
`12
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`IPR2022-01544
`Patent 7,289,961 B2
`D. Summary of Asserted Prior Art References
`1. Srinivasan (Ex. 1005)
`Srinivasan relates to an encoder that adds an inaudible binary code to
`an audio signal, and a decoder for retrieving that code, using a phase
`modulation scheme. See Ex. 1005, code (57), 1:5–7, 3:16–19, 11:25–30.
`The code “may be used . . . in order to identify a broadcast program.” Id. at
`1:8–10.
`Srinivasan’s Figure 1 follows:
`
`
`
`
`Figure 1 illustrates encoder 12 for adding codes to a digital
`representation of audio signal derived from audio signal portion 14 of a
`broadcast signal transmitted to receiver 20 for decoding the codes via
`decoder 26 and replaying the audio in speaker 24. See Ex. 1005, 7:29–41.
`After sampling an audio block to provide 512 samples and computing
`a Fast Fourier Transform (FFT) of the block (see steps 40–44, Fig. 2),
`
`13
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`IPR2022-01544
`Patent 7,289,961 B2
`Srinivasan’s “method comprises the following steps,” which result in phase
`encoding of frequency components of the audio signal:
`a) selecting, within the block, (i) a reference frequency within the
`predetermined signal bandwidth, (ii) a first code frequency
`having a first predetermined offset from the reference frequency,
`and (iii) a second code frequency having a second predetermined
`offset from the reference frequency; b) comparing the spectral
`amplitude of the signal near the first code frequency to the
`spectral amplitude of the signal near the second code frequency;
`c) selecting a portion of the signal at one of the first and second
`code frequencies at which the corresponding spectral amplitude
`is smaller to be a modifiable signal component, and selecting a
`portion of the signal at the other of the first and second code
`frequencies to be a reference signal component; and d)
`selectively changing the phase of the modifiable signal
`component so that it differs by no more than a predetermined
`amount from the phase of the reference signal component.
` Ex. 1005, 3:3–19.
`
`To select the frequencies to encode, Srinivasan’s method
`“determine[s] a frequency index Imax at which the spectral power of the audio
`signal, as determined as the step 44 [of Figure 2], is a maximum in the low
`frequency band extending from zero Hz to two kHz.” Ex. 1005, 8:51–54.
`Then, “[t]he code frequency indices 11 and 10 are chosen relative to . . . Imax
`so that they lie in a higher frequency band at which the human ear is
`relatively less sensitive.” Id. at 8:59–63. Srinivasan teaches that the less
`sensitive frequency ranges involve frequencies in the 4.8–6 kHz range “in
`order to exploit the higher auditory threshold in this band.” Id. at 7:64–67.
`“[E]ach successive bit of the code may use a different pair of code
`frequencies f1 and f0 denoted by corresponding code frequency indexes I1
`and I0.” Id. at 7:67–8:3. “[T]wo preferred ways of selecting the code
`frequencies f1 and f0 . . . create an inaudible wide-band noise like code.”
`
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`IPR2022-01544
`Patent 7,289,961 B2
`Id. at 8:3–5.
` Srinivasan’s Figure 3 follows:
`
`
`
`Srinivasan’s Figure 3 above, is a spectral plot illustrating the result of
`
`taking the FFT (Fast Fourier Transform) of a time block, where as a result of
`amplitude modulation coding, “spectrum 52 shows the audio block after
`coding of a ‘1’ bit, and a spectrum 54 shows the audio block before coding.”
`See Ex. 1005, 7:48–63. In other words, there is a visual difference between
`encoded audio waveform and the original audio waveform.
`
`Srinivasan describes one phase encoding technique as follows:
`In order to encode a binary number, the phase angle of one
`of these components, usually the component with the lower
`spectral amplitude, can be modified to be either in phase (i.e., 0°)
`or out of phase (i.e., 180°) with respect to the other component,
`which becomes the reference. In this manner, a binary 0 may be
`encoded as an in-phase modification and a binary 1 encoded as
`an out-of-phase modification.
`Ex. 1005, 11:26–32.
`
`To minimize the audible perception of coding the phase shifts,
`Srinivasan explains that “it is not essential to perform phase modulation to
`
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`IPR2022-01544
`Patent 7,289,961 B2
`th[e] extent of [a maximum phase change of 180°], as it is only necessary to
`ensure that the two components are either ‘close’ to one another in phase or
`‘far’ apart.” Id. at 11:49–54. Therefore, Srinivasan “assign[s] two phase
`neighborhoods,” “one ±45° (±π/4 radians) for a reference phase,” and
`another . . . ±45° of . . . 180° . . . out of phase with” the reference phase, to
`“represent a ‘0’ and ‘1,’” and then “modif[es] the phase angle . . . of the
`modifiable spectral component . . . into one of these phase neighborhoods
`depending upon whether a binary ‘0’ or a binary ‘1’ is being encoded.”
`Id. (citing Ex. 1005, 11:26–54). With this variation, “approximately 30% of
`the segments are ‘self-coded’ . . . and no modulation is required.” Id. at
`11:56–57.
`
`2. Kuduamakis (Ex. 1007)
`Kudumakis relates to “a method of labelling . . . an audio or video
`signal prior to broadcast or distribution to provide an audit trail.” Ex. 1007,
`1:4–8. Because prior art systems employed watermarking techniques using
`frequency notches at predictable frequencies to embed an inaudible code,
`Kudumakis “appropriately select[s] the part of the frequency spectrum
`where each watermark code is inserted, providing improved audio quality
`and extra security in the form of frequency hopping.” Id. at 2:23–25. The
`location in the frequency spectrum that includes the embedded code “is
`chosen adaptively with regard to the frequency content of the signal.” Id. at
`2:29–30. Therefore, Kudumakis’s frequency selection techniques introduce
`unpredictability as to the frequency location of the embedded codes. Id. at
`3:17–18.
`Kudumakis embeds the codes using the same notch filtering as the
`prior art, which places “notches” in the audio signal to remove the original
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`signal, and then replaces the removed signal with a frequency carrying the
`desired code using either amplitude or phase modulation. Ex. 1007, 1:17–
`18, 3:4–9, 6:1–2.
`
`For each input block, Kudumakis’s system “find[s] both the
`fundamental and its harmonics” of the audio input signal using known
`techniques such as FFT. Ex. 1007, 4:26–30. Using the fundamental and its
`harmonics to determine where to embed the codes enhances security against
`malicious attacks because those frequencies vary throughout the audio
`signal. Id. at 4:26–5:9. Kudumakis’s disclosed embodiments embed the
`notch filters and codes at the “edges” of “these harmonics.” Id. at 4:30–31.
`Codes are more perceptible if they “coincide with the main frequency
`component of the signal,” yet “they have to be placed in a part of the
`spectrum with sufficient energy so that frequent masking conditions can be
`met.” Id. at 3:5–9.
`
`3. Cabot (Ex. 1006)
`Cabot relates to testing “the audibility of phase shifts in two
`component octave complexes.” Ex. 1006, 568. The tests involved groups
`listening to “headphones with fundamental and third-harmonic signals” of an
`audio signal. Id.
`“The experiment shows phase shifts of harmonic complexes to be
`detectable, but judging from the difficulty experienced by the subjects, the
`effect appear to be small.” Ex. 1006, 570. In one experiment, subjects
`correctly identified a phase shift of 22.5 degrees between a fundamental and
`a harmonic with a 60 % corrected rate P. Id. at 570 (Table II). This appears
`to be a rate that “was only slightly better than chance,” where flipping a coin
`is a 50% chance. See id. at 568 (describing another experiment).
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`Cabot’s Figure 2a follows:
`
`
`Figure 2a above illustrates a time varying waveform (with time along
`
`the horizontal axis and amplitude along the vertical axis), which is equal to
`the sum of its fundamental harmonic at 400Hz plus its third harmonic at
`1200 Hz, as depicted.
`Cabot’s Figure 2b follows:
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`
`Figure 2b above illustrates a time varying composite signal (with time
`along the horizontal axis and amplitude along the vertical axis), which is
`equal to the sum of its fundamental harmonic at 400Hz plus its third
`harmonic at 1200 Hz, which is shifted by a phase of 90 degrees relative to
`the fundamental harmonic, as depicted. Notice that the composite signal in
`Figure 2a is different from the composite signal in Figure 2b, due to the
`relative phase shift of the third harmonic.
`Cabot reports that in a prior study, researchers “reported that their
`listeners were unable to detect a 180° phase shift in this same-different test
`arrangement.” Ex. 1006, 570. Cabot states that its “results, both
`quantitative and qualitative, correlate well with those of previous researchers
`using both similar and very different experimental techniques.” Id. at 571.
`In other words, “[a]lthough differences were detectable, they were subtle,”
`and “[t]his raises the question of its audibility compared to the more familiar
`forms of distortion.”
`
`E. Obviousness Ground 1: Based on Srinivasan, Cabot, and Kudumakis
`Petitioner contends that the subject matter of claims 1–10 would have
`been obvious over Srinivasan, Cabot, and Kudumakis. Pet. 2. Patent Owner
`argues that Petitioner’s showing is insufficient. Prelim. Resp. 24–43.
`
`1. Independent Claim 1
`a. Step 1PRE: “A method for embedding data in an audio
`signal, the method comprising:”
`
`Petitioner contends that “Srinivasan’s differential phase encoding
`method that ‘add[s] an inaudible code to an audio signal’ as ‘bit[s]’” satisfies
`the preamble. Pet. 29 (citing Ex. 1003 ¶ 139; quoting Ex. 1005, 1:5–7, 7:67)
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`Even if the preamble is limiting, the preliminary record supports
`Petitioner’s assertions and explanations. See Pet. 29 (citing Ex. 1003 ¶ 139;
`Ex. 1005, 1:5–7, 7:64–8:3), 9–14 (describing Srinivasan’s system).
` Petitioner sufficiently shows for institution purposes that Srinivasan
`teaches claim 1’s preamble. At this stage, Patent Owner does not allege any
`deficiencies in this aspect of Petitioner’s showing.
`b. Step 1A: “(a) dividing the audio signal into a plurality of time
`frames and, in each time frame, a plurality of frequency components”
`Petitioner contends that Srinivasan discloses this step. Pet. 29–31.
`According to Petitioner, Srinivasan discloses sampling an audio signal,
`dividing the digitized audio signal into a plurality of time frames called
`“blocks,” and then dividing each block into a plurality of frequency
`components by taking the FFT (Fast Fourier Transform). See id.
`(reproducing Ex. 1005, Figs. 2, 5; quoting id. at 7:33–42 (“a first block v(t)
`of jNc samples is derived from the audio signal portion 14 . . . where v(t) is
`the time-domain representation of the audio signal within the block”).
`The preliminary record supports Petitioner’s assertions and
`explanations. See Pet. 29–31 (reproducing Ex. 1005, Figs. 2, 5; citing id. at
`7:33–42, 9:47–49; Ex. 1003 ¶¶ 140–142). On this record, Petitioner
`sufficiently shows that Srinivasan teaches step 1A. At this stage, Patent
`Owner does not allege any deficiencies in this aspect of Petitioner’s
`showing.
`c. Step 1B: “(b) in each of at least some of the plurality of time
`frames, selecting at least two of the plurality of frequency components; and”
`Petitioner contends that Srinivasan’s method selects “two of the
`plurality of frequency components as the code frequencies f1 and f0 (also
`represented by frequency indices I1 and I0, respectively).” Pet. 32 (citing
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`Ex. 1005, 7:64–8:3; Ex. 1003 ¶ 143). Petitioner quotes Srinivasan as
`teaching that “[t]he code frequencies fi used for coding a block may be
`chosen from the Fourier Transform ℑ{v(t)} at a step 46” of Figure 2. Id.
`(quoting Ex. 1005, 7:64–66).
`Srinivasan’s Figure 2 follows:
`
`Srinivasan’s Figure 2 is a flow chart of steps performe