US 8320575

A concise summary of US Patent 8,320,575 is as follows:

Title: Efficient audio signal processing in the sub-band regime

Assignee: Cerence Operating Co.

Inventors: Gerhard Uwe Schmidt, Hans-Jörg Köpf, Günther Wirsching

Filing Date: September 30, 2008

Issue Date: November 27, 2012

Abstract:
A signal processing system enhances an audio signal. The audio signal is divided into audio sub-band signals. Some audio sub-band signals are excised. Other audio sub-band signals are processed to obtain enhanced audio sub-band signals. At least a portion of the excised audio sub-band signals are reconstructed. The reconstructed audio sub-band signals are synthesized with the enhanced audio sub-band signals to form an enhanced audio signal.

Plain-Language Overview of Independent Claims:

Claim 1: This claim describes a method for processing an audio signal to improve its quality. The core idea is to break the audio signal down into different frequency bands (sub-bands), remove some of these bands to make the processing more efficient, enhance the remaining bands, recreate the removed bands, and then combine everything back into a single, improved audio signal.

Claim 10: This claim outlines a similar method to claim 1 for enhancing an audio signal by dividing it into sub-bands and temporarily removing some for efficiency. However, this claim specifically details that the enhancement process involves using a second, "reference" audio signal. This reference signal is also broken into sub-bands, with a corresponding set of bands removed. The remaining bands of the reference signal are then used to help an "echo compensation filter" remove echo from the primary audio signal's remaining sub-bands.

A search of the U.S. Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 revealed no pending or recent litigation involving US Patent 8,320,575.