Echo Reducer With Frequency-Dependent Attenuation
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Solution Overview
Problem
Conventional voice communication devices struggle to effectively reduce echoes when both transmission and reception signals contain sound, as existing loss controllers attenuate signals uniformly regardless of frequency, leading to inadequate echo suppression.
Innovation Solution
An echo reduction system that includes an obtainer to determine frequency characteristics of the transmission system, a determiner to assess the presence of sound in both signals, and an attenuator to adjust the reception signal based on these characteristics, specifically attenuating frequencies likely to cause echoes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a loss controller attenuates a reception signal uniformly regardless of frequency, then the device structure remains simple, but the echo reduction effectiveness deteriorates
Solution Approach 1:
The patent applies local quality by making the attenuation characteristics frequency-dependent rather than uniform. The loss controller is configured to apply different attenuation levels to different frequency components of the reception signal, specifically targeting frequencies that are prone to causing echoes while preserving other frequency components. This resolves the contradiction by sacrificing uniformity (simplicity) in exchange for targeted effectiveness in echo reduction.
Solution Approach 2:
The patent changes the parameter of attenuation from a constant value to a frequency-dependent variable. By adjusting the attenuation level according to frequency characteristics, the system achieves better echo suppression performance. The loss controller modifies the reception signal based on frequency-specific attenuation characteristics, thereby improving echo reduction effectiveness without requiring complex additional hardware structures.
2Object-generated harmful factors
If frequency-specific attenuation is applied to reduce echoes, then echo reduction effectiveness improves, but device complexity increases
Solution Approach 1:
The loss controller performs multiple functions: it acts as both a signal attenuation device and an echo suppression device. By configuring the loss controller to apply frequency-dependent attenuation, it simultaneously achieves signal level control and echo reduction without requiring separate dedicated echo cancellation hardware. This multi-functionality approach improves echo reduction effectiveness while avoiding proportional increases in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces echoes during double talk by targeting specific frequency ranges, preventing echo return while maintaining voice clarity, and can be applied to various voice communication devices, including audio conferencing systems.
Implementation Method 1
an attenuator configured to attenuate the reception signal to be output to the sound emitter by attenuation characteristics corresponding to the frequency characteristics of the transmission system
Data Source
AI summary
An echo reducer includes: an obtainer configured to obtain frequency characteristics of a transmission system from a sound emitter of a sound emission and collection device to a sound collector of the sound emission and collection device; a determiner configured to determine whether or not both a transmission signal and a reception signal in the sound emission and collection device are in a state of including a sound; and an attenuator configured to attenuate the reception signal to be output to the sound emitter, by attenuation characteristics corresponding to the frequency characteristics of the transmission system that the obtainer obtains, when the determiner determines that both the transmission signal and the reception signal in the sound emission and collection device include a sound.