Audio Volume Normalization Using Dynamic Compression Phases

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Solution Overview

Problem

Existing methods for adjusting the volume of audio signals, particularly when playing back music files of different origins, require complex signal processing involving continuous transformation between time and frequency domains, which is inefficient and not directly addressing perceived loudness.

Innovation Solution

A method that dynamically compresses audio signals in the first phase to compare their volume with a target volume, adjusting it accordingly without continuous signal transformation, using Zwicker's loudness calculation and an intermediate phase for stepless adjustment, and setting default values based on audio sources to minimize volume discrepancies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If continuous signal transformation between time and frequency domains is performed, then volume adjustment accuracy is improved, but processing complexity and time consumption increase

Engineering Contradiction:
Improvevolume adjustment accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The audio signal processing is divided into distinct phases: a first phase where dynamic compression is applied to limit volume peaks, and a second phase where normal playback occurs. This segmentation allows volume adjustment without continuous complex signal transformation, reducing processing complexity while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Dynamic compression is applied in advance during the first phase to limit the volume of audio signals before normal playback. This preliminary action prevents volume exceeding without requiring continuous monitoring and transformation during playback, thereby reducing processing complexity while ensuring accurate volume control.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If dynamic compression is applied to limit volume, then volume control is simplified, but audio signal quality may deteriorate

Engineering Contradiction:
Improvevolume control complexityVSAvoidaudio signal quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system dynamically adjusts the compression ratio and threshold parameters based on the specific audio signal characteristics. By making the compression parameters adaptive rather than fixed, the system maintains audio quality while achieving effective volume control, resolving the contradiction between simplified control and signal quality.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3118993B1Method for adjusting the volume of audio signals of different volumes
Publication Date: 2019.12.04 ASK IND GMBH
  • EP3118993B1 patent drawingFigure 1~2
  • EP3118993B1 patent drawingFigure 3~6
  • EP3118993B1 patent drawingFigure 7

AI summary

The invention relates to a method for adjusting the volume of audio signals of different volumes, in particular stored music files from different audio sources that are played back successively as a sequence of sounds, characterized by the steps: specifying a target volume for all audio signals to be played back successively; determining the volume of an audio signal in a first phase of its playback; applying dynamic compression to the audio signal during this first phase; after completion of the volume determination during the first phase, increasing or decreasing the volume to adapt to the target volume during a second phase; and terminating the application of dynamic compression to the audio signal at the transition from the first phase to the second phase.