Noise Suppression Device With Time-Frequency Attenuation
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Solution Overview
Problem
Conventional noise suppression technologies often result in excessive or insufficient noise suppression due to errors in noise estimation and variations in noise suppression coefficients, leading to musical noise and unnatural sound quality.
Innovation Solution
A noise suppression device that estimates noise components and calculates multiple suppression coefficients in both time and frequency domains to generate an acoustic signal with suppressed noise, using a feature quantity calculating unit, estimating unit, first and second attenuating units, and a generating unit to ensure smooth coefficient variations and natural sound preservation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional noise suppression technology (spectral subtraction or Wiener filtering) is used, then noise suppression is achieved, but excessive or insufficient noise suppression occurs due to errors in noise estimation, leading to musical noise and unnatural sound quality
Solution Approach 1:
The patent applies dynamics by making the noise suppression coefficients adaptive and time-varying. Instead of using fixed coefficients, the system dynamically adjusts suppression coefficients based on the current acoustic signal characteristics and noise estimates, allowing the system to respond to changing environmental conditions and prevent both excessive and insufficient noise suppression
Solution Approach 2:
The patent implements feedback mechanisms where the estimated noise components and acoustic signal characteristics are continuously fed back into the noise suppression process. This feedback loop allows the system to refine its noise estimation and adjustment coefficients in real-time, improving the accuracy of noise suppression and reducing artifacts like musical noise
2Object-affected harmful factors
If noise suppression coefficients are adjusted to suppress noise, then noise component is reduced, but voice component may be excessively suppressed or not sufficiently suppressed
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different frequency components and temporal segments. The system calculates noise suppression coefficients separately for different frequency bands and applies them selectively, allowing aggressive noise suppression in noise-dominated frequencies while preserving voice components in voice-dominated frequencies
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting multiple noise suppression coefficients based on changing acoustic conditions. The system modifies coefficients in the time domain and frequency domain, allowing flexible control over the balance between noise suppression and voice preservation under varying environmental conditions
Data Source
AI summary
A noise suppression device includes an estimating unit that estimates, from a feature quantity representing the feature in each frequency range of a first acoustic signal which represents sound, the noise component of the feature quantity; a calculating unit that calculates, from the feature quantity and the noise component for each frequency range, a first suppression coefficient to be used in suppressing noise included in the first acoustic signal; a first attenuating unit that attenuates the first suppression coefficient in the time domain and calculates a second suppression coefficient; a second attenuating unit that attenuates the second suppression coefficient in the frequency domain and calculates a third suppression coefficient; and a generating unit that estimates, from the feature quantity and the third suppression coefficient, a voice component of the feature quantity and generates a second acoustic signal in which the noise included in the first acoustic signal is suppressed.