The Software IP Report

Audio Compression Improvements are Patent-Eligible

The Northern District of California recently held that claims directed to data compression to improve audio signal processing are eligible under 35 U.S.C. § 101 as improvements to computer operation. Hybrid Audio, LLC v. Asus Comput. Int’l, Case No. 3:17-cv-05947-JD (N.D. Cal. Jul. 11, 2019).

Hybrid Audio sued Asus for infringement of U.S. Reissue Patent No. RE40,281. The patent is directed to audio signal processing for compression systems for formats such as MP3. Defendant moved to dismiss under Rule 12(b)(6), alleging that the claims of the ‘281 patent were ineligible abstract ideas with no inventive concept. Under the first part of the two-part test of Alice v. CLS Bank, 573 U.S. 208 (2014), if a claim is not directed to an abstract idea, then the claim is eligible under Section 101 and the second step need not be considered.

The Court considered claim 5 as representative, which recites:

A signal processing method comprising:

splitting a signal into subbands using a plurality of filter banks connected to form a tree-structured array having a root node and greater than two leaf nodes, each node comprising one filter bank having greater than two filters, and at least one of the leaf nodes having a number of filters that differs from the number of filters in a second leaf mode.

The Court held that claim 5 “assert[s] a specific and tangible improvement to computer functionality, namely the processing of audio data, that is not abstract.” That is, the claimed improvements to multi-carrier transmission systems that limit the need for specialized computer equipment embodied improvements to computers that the Court found as not abstract, relying on reasoning from Core Wireless v. LG Elecs., 880 F.3d 1356 (Fed. Cir. 2018), among other cases. The Court noted that the claims included the “specificity required to transform a claim from claiming only a result to one claiming a way of achieving it.” While the claim covers a mathematical algorithm, the algorithm is used to improve a technological process (namely, to reduce errors in processing) that is concrete enough to survive step one of the Alice test.

Lessons for Practice

              Courts have recently looked for improvements in computer function to find claims eligible under Section 101. While the Court’s assertion that “plain language [that] leaves no reasonable doubt that the representative claims are directed to a specific improvement in the way computers operate” may be a bit stronger than other cases show, focusing claims on specific improvements to computer operation appears to be a useful strategy to survive Section 101 challenges.