Audio Loudness Matching Using Local Psychoacoustic Maxima

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Solution Overview

Problem

Existing audio processing systems require significant computing and storage resources to adjust audio signals from different sources to match subjective loudness, often distorting the audio by altering dynamics or using complex algorithms.

Innovation Solution

A method and device that dynamically adjust audio signals from different sources in real-time to match a psychoacoustic loudness target value using amplification calculated as the quotient of a nominal loudness value and average psychoacoustic loudness maximum, without relying on future data, allowing for efficient processing with minimal computing power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex algorithms (equalizers, compressors, limiters) are used to adjust audio volume, then loudness adaptation is achieved, but computing and storage capacity requirements increase significantly

Engineering Contradiction:
Improveloudness adaptation accuracyVSAvoidcomputing and storage capacity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for loudness adjustment by determining local loudness maxima within fixed time intervals, rather than processing the entire audio signal through complex algorithms. This selective extraction of critical data points (loudness maxima) reduces computing requirements while maintaining adaptation accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary smoothing of the control signal based on local loudness maxima before applying it to the audio output. By pre-processing the control signal in this manner, the system avoids the need for complex real-time processing during audio playback, reducing instantaneous computing demands

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If complex algorithms are used for volume adjustment, then loudness matching is improved, but audio dynamics are reduced and distortion occurs

Engineering Contradiction:
Improveloudness matching accuracyVSAvoidaudio dynamics
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent applies partial action by adjusting only the portions of the audio signal that exceed the loudness target value, rather than uniformly processing the entire signal. By focusing adjustment efforts only on exceeded maxima and applying smoothed control signals, the system achieves loudness matching while preserving the natural dynamics and transient characteristics of the audio content

Inventive Principle:
Principle #16Partial or excessive action

3Speed

If real-time processing is performed without future data, then processing speed is improved, but adaptation precision may be reduced

Engineering Contradiction:
Improvereal-time processing speedVSAvoidloudness adaptation precision
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent performs preliminary determination of local loudness maxima within fixed time intervals before final control signal generation. This advance preparation of control data allows the system to operate in real-time without requiring future audio data, while the fixed-time-interval analysis ensures sufficient precision for accurate loudness adaptation

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3190700B1Method and device for processing audio signals
Publication Date: 2020.10.07 FORD GLOBAL TECH LLC
  • EP3190700B1 patent drawingFigure 1
  • EP3190700B1 patent drawingFigure 2
  • EP3190700B1 patent drawingFigure 3~4

AI summary

The invention relates to a method and a device for processing audio signals. In an inventive method for processing audio signals in an entertainment system, audio signals from at least one audio source are modified during playback by the entertainment system to adapt them to a psychoacoustic loudness setpoint, wherein this modification is based on an average psychoacoustic loudness maximum determined for the respective audio source over a predetermined time interval.