US 11798576

A thorough analysis of US Patent 11,798,576 reveals an invention focused on enhancing in-vehicle communication systems by adaptively controlling audio gain based on real-time signal-to-noise ratios.

Title: Methods and apparatus for adaptive gain control in a communication system

Assignee: The patent is currently assigned to Cerence Operating Co.

Inventors:

• Tobias Herbig
• Meik Pfeffinger
• Bernd Iser

Filing Date: November 1, 2019

Issue Date: October 24, 2023

Abstract:
The patent describes methods and apparatuses for a communication system, typically within a vehicle, that utilizes microphones and loudspeakers. The system determines noise and speech level estimates from a received audio signal, calculates a signal-to-noise ratio (SNR), and then adjusts the gain of the signal to maintain a pre-selected SNR range at a specific position, such as a listener's ear. The gain adjustment involves adapting an actual gain to follow a target gain, which is itself adjusted to achieve the desired SNR range.

Overview of Independent Claims:

This patent has three independent claims: a method claim (Claim 1), an article of manufacture claim (Claim 12), and a system claim (Claim 18).

Claim 1 (Method): This claim outlines a method for controlling gain in a communication system. The core of the method involves:

1. Transforming a microphone signal into the frequency domain.
2. Estimating the noise and speech levels within that signal.
3. Calculating a Signal-to-Noise Ratio (SNR) from these estimates.
4. Adjusting the audio gain to keep the SNR at a listener's position within a predefined range (e.g., between a minimum and maximum SNR). This adjustment is made by comparing a continuously adapting "actual gain" to a "target gain" and incrementally changing the actual gain. The gain is increased if the SNR is too low and decreased if it is too high.

In plain language, this claim protects the specific process of actively managing the loudness of an in-car communication system to ensure clarity without being jarring. It does so by constantly monitoring the speech and noise levels and making smooth adjustments to the amplification.

Claim 12 (Article of Manufacture): This claim covers a non-transitory computer-readable medium (such as a hard drive or memory chip) that stores instructions for a machine. These instructions, when executed, cause the machine to perform the same method described in Claim 1.

Essentially, this claim protects the software or firmware that implements the adaptive gain control method. It prevents others from selling or distributing software that performs this specific set of steps for controlling audio gain in a communication system.

Claim 18 (Communication System): This claim describes the physical system itself. The system comprises:

• Microphones to capture sound.
• Loudspeakers to output sound.
• A sound processing module to transform the microphone signal.
• Noise and speech estimation modules.
• A gain control module with an SNR module and a gain module.
  This gain module, containing a processor, is configured to perform the adaptive gain control method as detailed in Claim 1.

This claim protects the tangible hardware assembly configured to execute the patented method. It covers the combination of microphones, speakers, and processors that work together to create the adaptive in-vehicle communication environment.

As of today's date, a search of the 2026 dockets for the U.S. Court of Appeals for the Federal Circuit (CAFC) did not yield any public records of litigation involving US Patent 11,798,576.