Noise-Adaptive Audio Playback for Consistent Perceived Loudness

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Solution Overview

Problem

Existing audio systems fail to maintain a consistent perceived loudness level in the presence of additive noise, leading to variations in sound output that can be distracting and inconvenient for users.

Innovation Solution

An automated noise adaptive playback system that adjusts the audio signal level based on detected background noise, using a common point mathematical relationship to maintain a desired perceived sound level, regardless of volume settings, through a processor-driven algorithm and circuitry that determines the necessary gain adjustments for the amplifier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If automated noise adaptive playback system adjusts audio signal level based on background noise, then perceived loudness consistency is improved, but device complexity increases

Engineering Contradiction:
Improveperceived loudness consistencyVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system dynamically changes the audio signal level parameter based on detected background noise levels. The processor adjusts the gain parameter in real-time according to the noise environment, maintaining consistent perceived loudness without requiring complex hardware modifications.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements a feedback loop where the processor continuously monitors background noise levels and automatically adjusts the audio signal level accordingly. This closed-loop control maintains perceived loudness consistency by comparing the desired output level with actual conditions and making real-time corrections.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If audio signal level is dynamically adjusted to compensate for background noise, then perceived loudness is maintained, but processing requirements increase

Engineering Contradiction:
Improveperceived loudnessVSAvoidprocessing requirements
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary noise level assessment and pre-calculates the required gain adjustment before audio playback. By determining the appropriate compensation level in advance based on the current noise environment, the processor reduces real-time computational requirements while maintaining perceived loudness consistency.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If common point mathematical relationship is used for noise compensation, then adaptability to different volume settings is improved, but algorithm complexity increases

Engineering Contradiction:
Improveadaptability to volume settingsVSAvoidalgorithm complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The common point mathematical relationship serves as a universal solution that works across all volume settings and noise conditions. This single algorithmic approach handles multiple scenarios (different volumes, various noise levels) without requiring separate compensation schemes, thereby improving adaptability while keeping the overall system manageable.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2395659B1Adaptive audio output
Publication Date: 2015.02.25 NXP BV
  • EP2395659B1 patent drawingFigure 1
  • EP2395659B1 patent drawingFigure 2
  • EP2395659B1 patent drawingFigure 3

AI summary

Devices, apparatus, methods, circuits and processors are implemented for control of audio signals. Consistent with one such apparatus, a processor circuit is configured and arranged to determine, for a perceived loudness algorithm that outputs audio signal levels, a common point corresponding to a particular background noise level at which the levels of the audio signal levels are independent of a volume setting that corresponds to desired perceived loudness, and to determine an audio signal level from the perceived loudness algorithm in response to a background noise signal, a volume setting signal, and the common point. An audio signal level output circuit is configured and arranged to provide an audio signal at the determined audio signal level.