Noise Reduction Apparatus Using Phase-Inverted Sudden Sound Suppression

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Solution Overview

Problem

Existing noise reduction techniques struggle to effectively suppress sudden sounds while maintaining the intelligibility of voice signals in noisy environments, particularly in scenarios where periodic noise, such as construction site vibrations or oxygen tank warnings, interferes with voice communication.

Innovation Solution

A noise reduction apparatus and method that involves storing sudden sound information from previous input signals, calculating correlation values and phase differences, shifting and inverting the sudden sound information to generate an addition signal, and adding it to the current input signal to suppress the sudden noise, thereby enhancing noise suppression without degrading voice quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If existing noise reduction techniques are applied to suppress sudden sounds, then the sudden sound suppression effect is improved, but the intelligibility of voice signals deteriorates

Engineering Contradiction:

Improvesudden sound suppression effectVSAvoidvoice intelligibility

Core Design Contradiction:

Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The patent stores sudden sound information from previous input signals before processing the current signal. By preparing the sudden sound information in advance from historical data, the system can quickly generate suppression signals without delaying voice processing, thus maintaining voice quality while achieving sudden sound suppression.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a copy of the sudden sound information from previous signals and uses this copied data to generate the addition signal for suppression. Instead of processing the current complex signal, the system copies and inverts the stored sudden sound pattern, which simplifies the suppression process and prevents voice signal degradation.

Inventive Principle:

Principle #26Copying

2Object-affected harmful factors

If signal processing is performed to suppress sudden noise, then the noise suppression effect is improved, but the processing complexity increases

Engineering Contradiction:

Improvesudden noise suppression effectVSAvoidsignal processing complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts only the sudden sound information from the input signal by comparing with stored historical data, rather than processing the entire complex signal. This extraction approach isolates the noise component that needs suppression while leaving the voice signal intact, reducing processing complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter of the stored sudden sound information by inverting its polarity and adjusting its phase based on correlation analysis. This parameter transformation allows the system to generate an effective suppression signal without complex filtering or decomposition algorithms.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If correlation calculation and phase adjustment are performed on sudden sound information, then the noise suppression precision is improved, but the processing time increases

Engineering Contradiction:

Improvenoise suppression precisionVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs correlation calculation between the current signal and stored sudden sound information in advance to determine the optimal phase shift. By preparing the phase adjustment value beforehand based on historical patterns, the system achieves precise suppression with minimal real-time processing delay.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical signal processing with computational correlation analysis. Instead of using traditional filtering methods that require extensive computational resources, the system uses correlation-based phase adjustment which is computationally more efficient while maintaining suppression precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9691407B2Noise reduction apparatus, noise reduction method, and noise reduction program

Publication Date: 2017.06.27 JVC KENWOOD CORP

AI summary

A noise reduction apparatus according to the present invention includes: a sudden sound information storage unit that stores an input signal that are input before a current input signal is input as sudden sound information, the input signal having a signal level of voice components equal to or smaller than a predetermined threshold and including a sudden sound to be suppressed; a phase difference calculation unit that calculates a phase difference between the sudden sound information and a sudden sound in the current input signal based on a maximum value of a correlation value between the sudden sound information and the current input signal; an addition signal generation unit that shifts a phase of the sudden sound information based on the phase difference to generate an addition signal; and a sudden sound suppression unit that adds the addition signal and the current input signal to output an output signal.