Opposite-Phase Speaker Tuning for Room Sound Leakage Suppression
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Solution Overview
Problem
Multi-channel audio devices can cause sound leakage outside the room when users listen to audio at preferred volume levels, disturbing others.
Innovation Solution
An audio system that outputs an audio reproduction signal from a reproduction speaker and an opposite-phase signal from an opposite-phase speaker, with pre-stored attenuation and delay settings to cancel out sound leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If audio reproduction signal is output from reproduction speaker at high volume level, then audio quality for user is improved, but sound leakage outside the room increases and disturbs others
Solution Approach 1:
The system applies preliminary anti-action by generating an opposite-phase signal before the sound leakage occurs. The opposite-phase speaker outputs a signal that is already inverted in phase relative to the reproduction speaker, creating destructive interference that cancels out the sound waves before they can leak outside the room. This proactive approach prevents the harmful effect rather than reacting to it after occurrence.
Solution Approach 2:
The system converts the harmful sound leakage into a beneficial cancellation effect. By taking the audio reproduction signal and inverting its phase, the system transforms the problematic sound waves into counter-waves that destructively interfere with the original sound, converting the harmful leakage into a useful noise-cancellation mechanism that protects neighbors while maintaining user audio quality.
2Object-generated harmful factors
If opposite-phase signal is output from opposite-phase speaker, then sound leakage is suppressed, but system complexity increases
Solution Approach 1:
The audio device serves as an intermediary that processes the audio reproduction signal and generates the opposite-phase signal. Rather than requiring direct connection between the reproduction speaker and opposite-phase speaker, the audio device mediates by receiving the reproduction signal, inverting its phase, applying attenuation and delay, then outputting to the opposite-phase speaker. This intermediary approach manages complexity by centralizing the signal processing function.
Solution Approach 2:
The system performs preliminary action by pre-calculating and storing attenuation rates and delay times for the opposite-phase signal. Instead of dynamically adjusting these parameters in real-time, the system determines the optimal attenuation and delay values in advance based on the acoustic environment, then applies them consistently. This preliminary calculation reduces computational complexity during actual operation while maintaining effective sound leakage suppression.
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
Effectively suppresses sound leakage outside the room by using opposite-phase speakers with pre-set attenuation and delay times, ensuring optimal audio experience within the room.
Implementation Method 1
audio output of an opposite-phase signal of this audio reproduction signal is executed from an opposite-phase speaker... with the opposite-phase signal attenuated based on the attenuation rate stored in advance and delayed based on the delay time stored in advance
Data Source
AI summary
[Problem] To provide a technology capable of suppressing sound leakage to the outside of a room even when a user listens to audio in the room at a preferred sound volume. [Solution] This multi-channel audio device 1 performs sound output on audio playback signals from channels through respective playback speakers 2, and performs sound output on antiphase signals of the audio playback signals through an antiphase speaker 3. The attenuation rates and the delay times of the audio playback signals output from the respective playback speakers 2 at the installation position of the antiphase speaker 3 are stored in advance, and during the audio playback, the antiphase signals of the audio playback signals of the respective channels are attenuated on the basis of the respective attenuation rates, are delayed on the basis of the respective delay times, and are output as sound from the antiphase speaker 3.