Impact Sound Suppression via Phase Continuity in Signal Processing

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Solution Overview

Problem

Existing noise suppression technologies fail to effectively address impact sound, leading to phase discontinuity and inadequate suppression, particularly in unexpected noise events like impact sounds.

Innovation Solution

A signal processing method that detects impact sound in noisy signals and processes phase information using phase data from the noisy signal, reducing phase changes to effectively suppress impact sound.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If impact sound suppression is applied only to magnitude spectrum without phase processing, then impact sound magnitude is reduced, but phase discontinuity remains causing insufficient suppression perception

Engineering Contradiction:

Improveimpact sound suppressionVSAvoidsuppression effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent segments the impact sound suppression process into two independent but coordinated components: magnitude spectrum processing and phase spectrum processing. The magnitude spectrum suppresses impact sound components while the phase spectrum is processed separately to maintain continuity. This segmentation allows each component to be optimized independently, resolving the contradiction by ensuring both magnitude reduction and phase continuity are achieved.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces phase information from non-impact sound portions as an intermediary to process the phase spectrum during impact sound events. Instead of directly processing the impacted phase information, the system uses phase data from unaffected portions as a mediator to maintain phase continuity, thereby preventing phase discontinuity while preserving impact sound suppression effectiveness.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If phase information from impact sound portions is used directly, then original phase characteristics are preserved, but phase discontinuity occurs reducing suppression quality

Engineering Contradiction:

Improvephase continuityVSAvoidphase information distortion

Core Design Contradiction:

Stability of the object's compositionVSLoss of information

Solution Approach 1:

The patent performs preliminary processing of phase information by extracting and storing phase data from non-impact sound portions before impact sound events occur. This preliminary action prepares clean, continuous phase information that can be applied during impact sound suppression, ensuring phase continuity is maintained without introducing distortion when impact sounds are present.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses phase information from non-impact portions as an intermediary substitute for directly using impacted phase information. This intermediary approach allows the system to maintain phase continuity by borrowing phase characteristics from unaffected portions, thereby avoiding phase discontinuity while minimizing information loss through a controlled substitution process.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9042576B2Signal processing method, information processing apparatus, and storage medium for storing a signal processing program

Publication Date: 2015.05.26 NEC CORP

AI summary

To sufficiently suppress an impact sound in a noisy signal.The impact sound in the noisy signal is suppressed. For this, the impact sound is detected in the noisy signal. It is characterized in that phase information of the detected impact sound is processed by using the phase information of a signal other than the impact sound in the noisy signal so that an amount of change in the phase information is reduced.