Dynamic Range Compression for Stable Masking Release

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Solution Overview

Problem

Traditional audio signal processing methods, such as broadband dynamic range compression, fail to dynamically adapt to input level variations over time, leading to sub-optimal masking release and signal-to-noise ratios, especially in audio content with wide dynamic ranges across various frequencies, resulting in compromised audio quality.

Innovation Solution

A method for determining operation parameters for a dynamic range compression system that dynamically adjusts the compression threshold based on the user's hearing profile, derived from demographic and hearing test data, to minimize sound intensity differences between maskee and masker, ensuring consistent masking release and improved signal detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If broadband dynamic range compression is applied to process the entire frequency spectrum with uniform parameters, then the system is simple to implement, but it cannot dynamically adapt to input level variations over time, resulting in sub-optimal masking release and signal-to-noise ratios

Engineering Contradiction:
Improvedynamic adaptation to input level variationsVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The frequency spectrum is divided into multiple frequency bands, each processed by an independent dynamic range compressor with its own threshold and ratio parameters. This segmentation allows each band to be adapted independently to input level variations, resolving the contradiction between adaptability and complexity by applying complexity only where needed in specific frequency regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compression threshold is made dynamic by continuously tracking the input signal level and adjusting the threshold accordingly. This dynamic adaptation allows the system to respond to input level variations over time, achieving the desired adaptability while maintaining reasonable system complexity through efficient threshold update mechanisms.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a fixed compression threshold is used across all frequencies, then the processing is computationally efficient, but the signal-to-noise ratio varies significantly when loud sounds are immediately followed by fainter sounds

Engineering Contradiction:
Improveconsistent signal-to-noise ratioVSAvoidprocessing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The compression threshold is dynamically adjusted based on the tracked input signal level. When the input level changes (e.g., from loud to faint sounds), the threshold adapts accordingly, maintaining a consistent signal-to-noise ratio across varying input conditions. This dynamic approach improves reliability while the efficient tracking algorithm maintains processing efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the input signal level to continuously adjust the compression threshold. By monitoring the input level and using this information to adapt the threshold, the system maintains consistent signal-to-noise ratio performance across different input conditions, resolving the contradiction between reliability and processing efficiency.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If multiband dynamic range compression is applied with frequency-specific parameters, then masking release and signal-to-noise ratios are improved, but the system complexity increases compared to broadband compression

Engineering Contradiction:
Improveaudio processing precisionVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The audio spectrum is segmented into multiple frequency bands, each processed with frequency-specific compression parameters. This segmentation enables precise control over masking release and signal-to-noise ratio in different frequency regions, achieving high processing precision. The modular structure of multiple independent compressors makes the complexity manageable and organized.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different compression parameters (threshold, ratio) are applied to different frequency bands based on their specific characteristics and requirements. This local quality approach allows optimal processing precision for each frequency region while maintaining overall system efficiency, balancing the trade-off between precision and complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS11323087B2Method to process an audio signal with a dynamic compressive system
Publication Date: 2022.05.03 MIMI HEARING TECHNOLOGIES GMBH
  • US11323087B2 patent drawing
  • US11323087B2 patent drawing
  • US11323087B2 patent drawing

AI summary

Disclosed is a method and apparatus for determining one or more operation parameters for a dynamic range compression (DRC) system. The method comprises obtaining, as an input, a parameter indicative of a hearing ability of a user, the parameter relating to a first difference in sound intensity between a maskee at a first frequency and a masker at a second frequency, determining a target value for the parameter, and determining the one or more operation parameters such that a second difference in sound intensity after sound intensity modification by the DRC (between sound intensity of the maskee of the masker) corresponds to the target value for the parameter. The operation parameters are determined such that a dependence of the second difference in sound intensity on the sound intensity of the maskee is minimized for a given range of sound intensities of the maskee.