Reverberation Suppression Using Instantaneous Envelope Analysis
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Solution Overview
Problem
Conventional reverberation suppression techniques require time-consuming assessment of reverberations, leading to errors in audio quality and increased data processing, which raises production costs.
Innovation Solution
A reverberation suppression apparatus that calculates instantaneous values in an input signal's envelope, estimates reverberation components using exponential moving averages, derives gains based on these values, and applies smoothing to adjust the signal amplitude, thereby simplifying data processing and reducing assessment time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reverberation suppression techniques using inverse filters are used, then reverberation can be removed from acoustic signals, but the assessment process takes too much time and increases data processing complexity
Solution Approach 1:
The patent changes the fundamental parameters of reverberation assessment by using instantaneous energy values and their exponential moving averages instead of conventional inverse filter methods. This parameter transformation enables real-time reverberation suppression without time-consuming assessments, directly resolving the contradiction between suppression effectiveness and assessment time
Solution Approach 2:
The patent replaces the complex mechanical data processing system of inverse filters with a simpler computational approach based on energy envelope analysis and exponential moving averages. This substitution maintains reverberation suppression effectiveness while dramatically reducing processing time and complexity
2Reliability
If conventional reverberation suppression techniques are used, then reverberation can be suppressed, but data processing amount increases which raises production costs
Solution Approach 1:
The patent extracts only the essential features needed for reverberation suppression by focusing on instantaneous energy values and their exponential moving averages, rather than processing complete acoustic signals through complex inverse filters. This extraction reduces data processing complexity while maintaining suppression effectiveness
Solution Approach 2:
The patent segments the reverberation suppression process into distinct computational stages: instantaneous energy calculation, exponential moving average computation, and gain derivation. This segmentation simplifies the overall data processing complexity by breaking down the complex inverse filter operation into manageable, efficient steps
Data Source
AI summary
A reverberation suppression apparatus includes: an instantaneous value calculation unit that calculates an instantaneous value/instantaneous values in an envelope of values correlating with the absolute value or the square of an input signal; a reverberation estimation unit that calculates an exponential moving average of the instantaneous value(s) as an estimated reverberation component; a gain derivation unit that derives a gain corresponding to the input signal according to the estimated reverberation component and the instantaneous value(s) when the each instantaneous value is larger than the estimated reverberation component, and derives a lower limit of the gain as the gain corresponding to the input signal when the each instantaneous value is smaller than the estimated reverberation component; a smoothing unit that performs a smoothing process on the gain; and a gain processing unit that applies the gain to amplitude adjustment of the input signal thereafter.