PTAB challenges

Proceedings overview

There are two Inter Partes Review (IPR) proceedings on file for U.S. Patent No. 11,921,355, both initiated by [Apple Inc.](/litigations/by-plaintiff/Apple%20Inc.) and currently pending institution. This indicates that the patent is actively being challenged, and the defensive posture for a defendant facing assertion is that the patent's claims are under scrutiny and have not yet been hardened by surviving an IPR to a Final Written Decision.

IPR2026-00332 — Apple Inc. v. Ingeniospec LLC

• Type: Inter Partes Review
• Filed: 2026-04-03
• Status: Pending – The Board has not yet determined whether to institute a trial.
• Judge panel: Not yet publicly available, as institution has not occurred.
• Petition grounds: Details of the specific claims challenged and prior art asserted are not yet publicly available without access to the petition itself, which is typically made public upon institution. However, based on the related litigation (1:25-cv-00867), it is likely that claims related to a "head-worn personal device" where speakers near the ear are used with a mobile device utilizing a hearing profile to output signals are targeted. These would typically be challenged under 35 U.S.C. § 102 (anticipation) and/or § 103 (obviousness) in view of prior art.
• Institution decision: Not yet issued. The statutory deadline for the institution decision is typically six months from the petition's filing date, placing it around 2026-10-03.
• Final Written Decision (if issued): Not applicable, as institution has not occurred.
• Settlement / termination: No settlement or termination has been recorded as the proceeding is in the pre-institution phase.
• Appeal: Not applicable, as no Final Written Decision has been issued.
• Defensive value: This IPR indicates an active challenge to the patent's validity by a significant operating company. Should this IPR be instituted and result in claims being cancelled, it would significantly weaken Ingeniospec LLC's assertion capabilities. Conversely, if institution is denied or claims are upheld, it would strengthen the patent.

IPR2026-00331 — Apple Inc. v. Ingeniospec LLC

• Type: Inter Partes Review
• Filed: 2026-04-03
• Status: Pending – The Board has not yet determined whether to institute a trial.
• Judge panel: Not yet publicly available, as institution has not occurred.
• Petition grounds: Similar to IPR2026-00332, the specific claims challenged and prior art are not yet public. Given the parallel filing with IPR2026-00332, it is highly probable that this petition targets different claims or presents alternative grounds of unpatentability for overlapping claims of US 11921355. These challenges would typically rely on 35 U.S.C. § 102 and/or § 103.
• Institution decision: Not yet issued. The statutory deadline for the institution decision is typically six months from the petition's filing date, placing it around 2026-10-03.
• Final Written Decision (if issued): Not applicable, as institution has not occurred.
• Settlement / termination: No settlement or termination has been recorded as the proceeding is in the pre-institution phase.
• Appeal: Not applicable, as no Final Written Decision has been issued.
• Defensive value: This parallel IPR by Apple Inc. demonstrates a concerted effort to invalidate the '355 patent. The outcome of this proceeding, alongside IPR2026-00332, will be critical in determining the patent's strength and the viability of infringement contentions.

Strategic summary

Currently, all claims of U.S. Patent No. 11,921,355 are UNTESTED by a Final Written Decision from the PTAB. Both IPR2026-00332 and IPR2026-00331 are in the pre-institution phase, meaning the PTAB has not yet decided whether to formally initiate a trial on the patentability of the challenged claims. Therefore, no claims have been canceled or explicitly sustained by the PTAB to date.

The estoppel landscape is not yet established for these proceedings, as no Final Written Decisions have been rendered. However, if institution occurs and a Final Written Decision issues, Apple Inc. (and its privies) would be estopped under 35 U.S.C. § 315(e)(2) from asserting in future litigation that a claim is invalid on any ground that Apple raised or reasonably could have raised in these IPRs. The pattern signals clearly show that Apple Inc. is a repeat petitioner, filing two separate IPRs against the same patent on the same day, indicating a strong commitment to challenging its validity.

Recommended next steps

Both IPR2026-00332 and IPR2026-00331 are pending institution decisions. As a defendant, the critical next milestone to monitor for both proceedings is the institution decision deadline, which is around 2026-10-03. These decisions will reveal which claims, if any, the PTAB believes are likely unpatentable and will proceed to trial. The full petitions for these IPRs are not yet public via the USPTO PTAB E2E portal, but will become available if institution is granted. Monitoring the USPTO PTAB E2E portal for updates on these case numbers is essential for understanding the specific arguments and prior art presented by Apple and the PTAB's initial assessment of those arguments.