Phase Difference Signal Processing for Diffuse Noise Estimation
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Solution Overview
Problem
Existing techniques fail to accurately estimate interfering sounds arriving from various directions, such as environmental noise and diffuse noise, which affects the quality of signal processing in mixed sound environments.
Innovation Solution
A signal processing apparatus and method that calculates the phase difference between input signals from environments with mixed target and interfering sounds, generating an estimated interfering sound signal to suppress unwanted noise and enhance the target sound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional noise suppression techniques are used, then processing is simple, but diffuse interfering sounds arriving from various directions cannot be estimated accurately
Solution Approach 1:
The patent segments the interfering sound estimation into two distinct components: a directional interfering sound component estimated using conventional techniques, and a diffuse interfering sound component estimated using the phase difference method. This segmentation allows accurate estimation of diffuse sounds without completely replacing existing simple methods, thereby balancing precision improvement with complexity management.
Solution Approach 2:
The patent introduces phase difference as an intermediary parameter to estimate diffuse interfering sounds. By calculating the phase difference between multiple input signals and using it to generate an estimated interfering sound signal, the system can accurately capture diffuse sound characteristics without requiring complex directional modeling, thus achieving high precision with controlled complexity.
2Measurement precision
If phase difference calculation is added to estimate diffuse noise, then estimation accuracy improves, but processing complexity increases
Solution Approach 1:
The patent applies partial action by focusing phase difference calculation only on the diffuse interfering sound component rather than processing all sound components. This selective application of the complex phase difference method to only the necessary diffuse noise portion achieves accurate estimation while limiting the increase in processing complexity to what is strictly required.
3Object-affected harmful factors
If conventional beamforming is used, then directional noise suppression works, but environmental noise and wind noise from various directions cannot be suppressed
Solution Approach 1:
The patent creates a multi-functional noise suppression system that combines conventional directional beamforming with the new phase difference-based diffuse noise estimation. This universal approach allows the system to handle both directional and diffuse noise types effectively, achieving broad-spectrum noise suppression capability while maintaining accurate estimation through the complementary nature of the two methods.
Data Source
AI summary
A signal processing apparatus, for processing sounds collected in an environment where a target sound and an interfering sound are mixed in order to estimate a diffuse interfering sound accurately, is provided. The signal processing apparatus includes phase difference calculating means and generating means. The phase difference calculating means calculates a phase difference between the first input signal and the second input signal. The first input signal is generated based on the first input sound which is input in the environment where the target sound and the interfering sound are mixed. The second input signal is generated based on the second input sound which is input in the environment. The generating means generates an estimated interfering sound signal, based on the phase difference and the first input signal.