Earin AB v. Audio-Technica U.S., Inc.

Earin AB, a Swedish audio technology company founded in 2014, specializes in the development and manufacturing of compact, high-quality wireless earphones. The company's products include wireless earbuds designed to connect to devices via Bluetooth, such as their M-1 and M-2 models. In contrast, the defendant, Audio-Technica U.S., Inc., is the American arm of a globally recognized Japanese audio equipment manufacturer established in 1962. Audio-Technica designs, manufactures, and distributes a wide range of audio products, including headphones, microphones, and turntables, serving both professional and consumer markets. While Earin AB is an operating company in the audio space, its pattern of asserting the same patent against multiple major audio companies, including Skullcandy Inc. and Sennheiser Electronic Corporation, suggests it may also act as a patent assertion entity (PAE) or non-practicing entity (NPE) in some instances.

The core of this litigation revolves around U.S. Patent No. 9,402,120, titled "Wireless earbuds." This patent generally describes improvements in wireless earbuds, particularly concerning the internal arrangement of components like the loudspeaker, rechargeable battery, printed circuit board, and charging interface along the longitudinal axis of the earbud housing. It also covers features related to a wireless audio streaming host device that communicates with first and second wireless earbuds and is configured to receive messages indicating battery charge status. While the specific accused Audio-Technica product or technology is not explicitly detailed in the immediately available public docket summaries for this case, given Audio-Technica's business and Earin's patent, it is highly likely that the accused products are Audio-Technica's wireless earbuds that allegedly incorporate the features claimed in the '120 patent. In a parallel case, Earin AB has accused Skullcandy's "Rail ANC True Wireless earbuds" of infringing at least claim 20 of the '120 patent.

The case, Earin AB v. Audio-Technica U.S., Inc., was filed on July 23, 2025, in the U.S. District Court for the Northern District of Ohio under case number 5:2025cv01534, with Judge John R. Adams presiding. An amended complaint for patent infringement was filed on January 16, 2026. The Northern District of Ohio is not typically among the top-tier venues for patent litigation like the District of Delaware or the Western District of Texas, which are known for their high volume of patent cases and specific procedural characteristics. However, the presence of Audio-Technica's US operations, including locations in Stow, Ohio, could provide a basis for venue in the Northern District of Ohio. The case's notability stems from Earin AB's apparent strategy of asserting the '120 patent against multiple established audio equipment manufacturers, which could indicate a broader enforcement campaign within the wireless earbud industry. This trend, coupled with ongoing discussions and IPRs related to the '120 patent in other litigations, highlights the competitive landscape and intellectual property disputes within the rapidly evolving personal audio device market.

Legal Developments in Earin AB v. Audio-Technica U.S., Inc.

The patent infringement lawsuit filed by Earin AB against Audio-Technica U.S., Inc. in the U.S. District Court for the Northern District of Ohio, case number 5:2025cv01534, remains active. The case primarily involves U.S. Patent No. 9,402,120.

Chronological Overview of Key Developments:

• 2025-07-23: Complaint Filed
  Earin AB initiated the litigation by filing a complaint for patent infringement against Audio-Technica U.S., Inc. in the Northern District of Ohio. A jury trial was demanded by the plaintiff.
• 2026-01-02: Pro Hac Vice Admissions
  Attorneys Gene Volchenko, Robert R. Walling, and Michael Jason Riesen were granted pro hac vice appearances to represent Audio-Technica U.S., Inc.
• 2026-01-16: Amended Complaint Filed
  Earin AB filed an amended complaint for patent infringement, formally asserting U.S. Patent No. 9,402,120 against Audio-Technica U.S., Inc.
• 2026-02-02: Motion to Dismiss Denied as Moot
  A motion to dismiss previously filed by Audio-Technica U.S., Inc. was denied as moot by Judge John R. Adams, due to the plaintiff's filing of the amended complaint on January 16, 2026. The details of the original motion to dismiss are not explicitly available, but it was likely directed at the initial complaint.

Parallel PTAB Proceedings:

• 2025-05-13: IPR Petition Filed against US Patent 9,402,120
  A separate inter partes review (IPR) proceeding, IPR2025-00690, was filed before the Patent Trial and Appeal Board (PTAB) challenging U.S. Patent No. 9,402,120. This IPR was initiated by Skullcandy, Inc. as the Petitioner, with Earin AB as the Patent Owner. Claims 20 and 21 of the '120 patent are specifically at issue in this IPR. The IPR petition was submitted to the PTAB on March 7, 2025.

Current Posture:

As of May 16, 2026, the district court case remains active, with initial pleadings concluded following the amended complaint and the mooting of an early motion to dismiss. There is no publicly available information indicating that Audio-Technica has filed an answer or counterclaims to the amended complaint, nor any subsequent substantive pre-trial motions (e.g., motions to dismiss the amended complaint, transfer, stay, or for summary judgment). The case has not yet reached the claim construction (Markman) stage, nor has it proceeded to discovery milestones, trial, or a final disposition.

The status of the parallel IPR2025-00690 proceeding against U.S. Patent No. 9,402,120 is not yet determined in terms of institution or a final written decision. The outcome of this IPR could significantly impact the district court litigation if the PTAB were to institute a review and subsequently invalidate claims of the patent. Skullcandy, a party in a related District of Delaware case involving the same patent, stipulated that it would not pursue the IPR grounds in that litigation if the IPR petition is granted.

Counsel representing Earin AB in Earin AB v. Audio-Technica U.S., Inc. (5:2025cv01534) includes attorneys from Webb Law Firm and Folio Law.

Here are the details of the identified counsel:

• Cristofer I. Leffler

  • Role: Likely lead counsel or a primary attorney. He filed the amended complaint on behalf of Earin AB.
  • Firm: Folio Law - Seattle
  • Office Location: Seattle, Washington.
  • Relevant Experience: Cristofer I. Leffler is listed as filing the amended complaint for patent infringement, indicating experience in patent litigation.

• Anthony W. Brooks

  • Role: Appears to be a primary attorney, having filed the initial complaint and a stipulation.
  • Firm: Webb Law Firm
  • Office Location: The docket entry for Webb Law Firm does not specify an office location, but the firm is headquartered in Pittsburgh, Pennsylvania.
  • Relevant Experience: Anthony W. Brooks filed the initial complaint for patent infringement.

• Cecilia R. Dickson

  • Role: Counsel.
  • Firm: Webb Law Firm
  • Office Location: The docket entry for Webb Law Firm does not specify an office location, but the firm is headquartered in Pittsburgh, Pennsylvania.
  • Relevant Experience: The docket identifies Cecilia R. Dickson as counsel for Earin AB. Further specific details on her patent litigation experience would require additional investigation beyond the immediate docket information.

The defendant, Audio-Technica U.S., Inc., is represented by the following counsel:

• Robert R. Walling (Lead Counsel, pro hac vice)
  • Firm: Banner Witcoff, Ltd.
  • Office Location: Washington, D.C.
  • Experience Note: Robert Walling is a principal at Banner Witcoff and focuses his practice on patent litigation, post-grant proceedings, and client counseling. He has experience in federal district courts across the U.S. and before the Patent Trial and Appeal Board.
• Michael Jason Riesen (Lead Counsel, pro hac vice)
  • Firm: Banner Witcoff, Ltd.
  • Office Location: Washington, D.C.
  • Experience Note: Michael Riesen is a principal at Banner Witcoff and concentrates his practice on patent litigation and other intellectual property disputes. He represents clients in district courts, before the ITC, and in inter partes review proceedings.
• Gene Volchenko (Lead Counsel, pro hac vice)
  • Firm: Banner Witcoff, Ltd.
  • Office Location: Washington, D.C.
  • Experience Note: Gene Volchenko is a principal at Banner Witcoff, focusing on patent litigation and appeals. His experience includes a wide range of technologies, and he has represented clients in numerous federal district courts and before the Federal Circuit.

Motions for appearance pro hac vice for Robert R. Walling, Michael Jason Riesen, and Gene Volchenko were granted by Judge John R. Adams on January 2, 2026. These attorneys are from Banner Witcoff, Ltd..