Adaptive Audio Loudness Control Under Changing Noise Conditions

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Solution Overview

Problem

Existing audio signal loudness control methods fail to dynamically adapt to changing noise environments, often resulting in unsatisfactory user experience as they maintain constant partial loudness, which does not align with user preferences under varying noise conditions.

Innovation Solution

A method and system that dynamically control the target partial loudness of an audio signal by considering factors related to the noise signal, the audio signal itself, and user preferences, using a combination of noise and audio type classifiers, level meters, and user input to derive a target partial loudness adjustment, which is then applied to maintain optimal perceived loudness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If constant partial loudness is maintained in presence of noise signal, then audio loudness consistency is improved, but user satisfaction deteriorates under varying noise conditions

Engineering Contradiction:
Improveaudio loudness consistencyVSAvoiduser satisfaction under varying noise conditions
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic target partial loudness adjustment by introducing a target partial loudness adjustment derivation unit that continuously adapts the target loudness level based on real-time noise signal characteristics and audio signal properties. Instead of maintaining a fixed target partial loudness, the system dynamically modifies the target value according to environmental conditions, thereby resolving the contradiction between stability and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of target partial loudness from a constant value to a variable value that depends on noise signal level, audio signal characteristics, and user preferences. This parameter transformation allows the audio loudness control to adapt to varying noise conditions while maintaining operational stability through structured adjustment mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If noise signal level increases, then background noise interference increases, but partial loudness of audio signal decreases

Engineering Contradiction:
Improvebackground noise interferenceVSAvoidpartial loudness of audio signal
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent employs feedback mechanisms by continuously monitoring the noise signal level and audio signal characteristics, then using this information to adjust the target partial loudness through the derivation unit. This closed-loop control ensures that as noise interference increases, the system responds by appropriately increasing the target loudness level to compensate for the masking effect, thereby maintaining audio signal clarity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary anti-action by proactively adjusting the target partial loudness before the audio signal becomes inaudible or unsatisfactory. The derivation unit anticipates the need for loudness compensation by detecting noise signal characteristics and pre-adjusting the target level, preventing the degradation of partial loudness rather than merely reacting to it.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3149970B1Audio signal loudness control
Publication Date: 2018.05.09 DOLBY LABORATORIES LICENSING CORP
  • EP3149970B1 patent drawingFigure 1~2
  • EP3149970B1 patent drawingFigure 3~6
  • EP3149970B1 patent drawingFigure 5~7

AI summary

Example embodiments disclosed herein relate to audio signal loudness control. A method for controlling loudness of an audio signal is disclosed. The method includes responsive to determining presence of a noise signal, deriving a target partial loudness adjustment based, at least in part, on at least one of a first factor related to the noise signal and a second factor related to the audio signal. The method further includes determining a target partial loudness of the audio signal based, at least in part, on the target partial loudness adjustment. Corresponding system, apparatus and computer program product are also disclosed.