Loudspeaker Speech Equalization Using Adaptive Compensation Filters

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Solution Overview

Problem

Existing loudspeaker systems, particularly in applications like speakerphones and telecommunication devices, often suffer from suboptimal frequency content in incoming speech signals due to poor microphone design, noise, and channel limitations, leading to reduced listening comfort and speech intelligibility.

Innovation Solution

A method for dynamic speech equalization that involves analyzing incoming audio signals using a speech analysis block to apply frequency-dependent adjustments through a combination of compensation and transparent filters, enhancing the signal's frequency response to match ideal speech characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If dynamic speech equalization with multiple filters is applied, then speech intelligibility is improved, but device complexity increases

Engineering Contradiction:
Improvespeech intelligibilityVSAvoidequalization unit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The equalization function is segmented into multiple independent compensation filters (first compensation filter, second compensation filter, etc.), each targeting specific frequency ranges or impairment types. This allows the system to process different frequency components separately and combine them to achieve comprehensive speech enhancement while maintaining modular architecture that manages complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and adjusts which compensation filters to apply based on real-time analysis of the input signal characteristics. The equalization unit can adaptively activate or deactivate specific filters depending on the detected speech conditions, making the processing complexity variable rather than fixed, thus balancing performance with computational load.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If frequency-dependent processing is applied to correct suboptimal frequency content, then listening comfort is improved, but processing time increases

Engineering Contradiction:
Improvelistening comfortVSAvoidsignal processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary analysis of the input signal to identify speech components and their frequency characteristics before applying the full equalization processing. This preliminary detection allows the system to prepare appropriate filter configurations in advance, reducing the actual processing time when enhancement is needed while maintaining listening comfort quality.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple compensation filters are dynamically applied, then speech intelligibility is improved, but computational power consumption increases

Engineering Contradiction:
Improvespeech intelligibilityVSAvoidprocessing power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The equalization unit dynamically activates only the necessary compensation filters based on real-time speech analysis, rather than continuously applying all filters. This adaptive approach ensures that computational resources and power are consumed only when and where needed to improve speech intelligibility, optimizing the balance between performance and energy efficiency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11600285B2Loudspeaker system provided with dynamic speech equalization
Publication Date: 2023.03.07 EPOS GROUP AS
  • US11600285B2 patent drawing
  • US11600285B2 patent drawing
  • US11600285B2 patent drawing

AI summary

A method for speech equalization, comprising the steps of receiving an input audio signal, processing said input audio signal in dependence on frequency and to providing an equalized electric audio signal according to an equalization function, wherein said equalization function comprises at least an actuator part configured to dynamically applying a compensation filter to the received input signal and dynamically applying a transparent filter to the received input signal, and further transmitting an output signal perceivable by a user as sound representative of said electric acoustic input signal or a processed version thereof.