IP Law Daily, PATENT—Fed. Cir.: Anticipation and obviousness affirmed in noise-cancelling earpiece dispute, (Nov 4, 2025)

By Kevin M. Finson, J.D.

Claim constructions underlying PTAB determinations of anticipation and obviousness were affirmed because they were supported by the plain language of the terms, expert testimony, and the forfeiture of arguments not squarely submitted below.

The owner of a patent for noise-cancelling earpieces failed to show any error in a PTAB decision invalidating many of the patent’s claims, the U.S. Court of Appeals for the Federal Circuit has held. The Board’s claim constructions were supported by intrinsic evidence and expert testimony (Cases2Tech, LLC v. Squires, No. 23-2290, (Fed. Cir. Nov. 4, 2025)).

Cases2Tech, LLC (Cases2) was the owner by assignment of U.S. Patent No. 8,315,400 (the ’400 patent), which claimed an earpiece and methods for using it that were capable of suppressing background noise by mixing the signals from two microphones, one located facing inwards towards the ear and one facing outwards to pick up ambient sound. Cases2’s predecessor in interest, Staton Techiya, LLC (Techiya) brought suit against Samsung Electronics Co. (Samsung) for infringement of the ’400 patent, among others. During the pendency of the litigation, Samsung petitioned for inter partes review of all 20 claims of the ’400 patent. The Patent Trial and Appeal Board (PTAB) instituted review and found seven claims anticipated and eight claims rendered obvious by a prior patent application publication. Techiya appealed, challenging the Board’s claim construction, and Samsung declined to participate in the appeal. The Director of the USPTO intervened to defend the Board’s decision, and the ’400 patent was, in the interim, assigned to Cases2.

Background noise level. Cases2 argued that the Board erred by construing the term “background noise level” to encompass a noise level in a subset of sound frequencies rather than limiting it to one, single background noise level. Reviewing the claim language, including context from other claims and the expert testimony in the record, the Federal Circuit held that while there was one general “background noise level,” there was nothing in the claim terms or specification to limit the meaning of that term in such a way that would exclude calculating a background noise level within several different frequency bands of the sound spectrum.

Adjustments based on background noise. Cases2 argued that the Board erred in construing a requirement that the amplitude of one or more frequencies be adjusted “based on” the background noise level in a way that was too broad. The prior art reference used two components in this process, a “noise reducer” and an “adaptive equalizer,” while the ’400 patent used only one, a “processor” to perform both functions. Cases2’s argument was that only the noise reducer received the background noise level and then the output of the noise reducer was used to adjust the amplitude of frequencies by the adaptive equalizer, so the adjustment was not “based on” the background noise level.

The Federal Circuit found that this narrowing construction, requiring both functions be performed by one component, was not squarely requested by Cases2 before the Board and was therefore waived. Even if not waived, there was no intrinsic evidence nor case law to support the proposed construction.

The Federal Circuit affirmed the decision of the Board.

The Case is No. 23-2290.

Judge: Taranto, R.

Attorneys: Timothy Devlin (Devlin Law Firm LLC) for Cases2tech, LLC. Mai-Trang Duc Dang, Office of the Solicitor General, for John A. Squires.

Companies: Cases2tech, LLC

Cases: Patent FedCirNews USPTO