Dynamic Low-Frequency Audio Enhancement via AGC Gain Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing audio signal processing technologies using static filters struggle to dynamically adjust gains for different frequencies at varying sound pressure levels, limiting optimal low-frequency enhancement according to equal-loudness contour requirements.

Innovation Solution

A method and system that dynamically enhance low frequencies by extracting high and low-frequency signals, applying dynamic gain processing using an AGC algorithm, and performing low-pass filtering, followed by weighted summation with specific weight coefficients to achieve equal-loudness contour alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If static filter combination is used for low-frequency enhancement, then the device structure is simple, but different gains cannot be added to signals of different frequencies at different sound pressure levels

Engineering Contradiction:

Improveability to add different gains to signals of different frequencies at different sound pressure levelsVSAvoidfilter combination structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent transforms the static filter combination into a dynamic system by introducing an AGC (Automatic Gain Control) module that continuously monitors sound pressure levels and dynamically adjusts the gain coefficients of different frequency bands. This allows the system to adaptively apply different gains to different frequencies based on real-time sound pressure conditions, resolving the contradiction between adaptability and device complexity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the gain parameters dynamically based on sound pressure level measurements. The AGC module calculates different gain coefficients for low-frequency, mid-frequency, and high-frequency bands according to the detected sound pressure level, enabling the system to meet equal-loudness contour requirements without requiring complex static filter combinations for every possible condition.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If pure filter technologies are used for low-frequency enhancement, then the implementation is simple, but voice volume adjustment cannot meet equal-loudness contour requirements

Engineering Contradiction:

Improveequal-loudness contour complianceVSAvoidvoice volume adjustment

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces a feedback mechanism where the AGC module continuously monitors the sound pressure level of the audio signal and uses this information to dynamically adjust the gain coefficients. This closed-loop feedback system ensures that voice volume adjustment automatically complies with equal-loudness contour requirements across different frequencies, eliminating the need for manual adjustment while maintaining reliability.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs automatic gain adjustment without requiring user intervention. The AGC module independently monitors sound pressure levels and dynamically modifies the gain coefficients for different frequency bands, enabling the system to self-adjust and maintain equal-loudness contour compliance during voice volume changes.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If different gains are added to signals of different frequencies at different sound pressure levels, then optimal low-frequency enhancement is achieved, but the system complexity increases

Engineering Contradiction:

Improvelow-frequency enhancement effectVSAvoiddynamic gain processing system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the audio signal into different frequency bands (low-frequency, mid-frequency, and high-frequency bands) and applies independent gain control to each band through separate filtering paths. The AGC module calculates and applies different gain coefficients to each segment based on sound pressure level, achieving precise low-frequency enhancement while managing system complexity through modular segmentation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10511905B2Method and system for dynamically enhancing low frequency based on equal-loudness contour

Publication Date: 2019.12.17 SHENZHEN GRANDSUN ELECTRONICS CO LTD

AI summary

A method comprises: collecting an input audio signal; performing frequency-division processing on the input audio signal, extracting a high-frequency signal and a low-frequency signal to transmit respectively, and reserving one path of original audio signal; performing dynamic gain processing on the low-frequency signal adopting an Automatic Gain Control (AGC) algorithm, and performing low-pass filtering enhancement processing on the original audio signal adopting a static low-frequency enhancement algorithm; and subjecting the high-frequency signal, the processed low-frequency signal and the processed original audio signal to weighted summation to obtain a final output audio signal, the weight coefficients of the high frequency signal, the processed low-frequency signal and the processed original audio signal being a, b and c respectively, where the values of a, b and c range from 0 to 1, and a+b+c=1.