Time-Variant Beam Pattern for Directional Sound Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional array speaker systems struggle to effectively focus sound on specific areas while minimizing noise pollution, as they rely on fixed beam patterns that can lead to unwanted sound pressure variations due to interference from reflected waves, reducing the difference in sound pressure between desired and undesired areas.
Innovation Solution
The apparatus generates a time-variant beam pattern with an attenuation rate dependent on distance, using a beam pattern generating unit that convolutes the sound source signal to produce a multi-channel signal, allowing for dynamic adjustment of sound pressure based on location, thereby reducing interference and maintaining consistent direct wave magnitude in the listening area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed beam pattern is used in conventional array speaker systems, then the system structure is simple and easy to implement, but sound pressure variations occur due to interference from reflected waves, reducing the difference in sound pressure between desired and undesired areas
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed beam pattern to a time-variant beam pattern that changes over time. The beam pattern is updated periodically based on the impulse response characteristics of the reproduction space, allowing the system to adapt to reflected waves and maintain effective sound pressure differences between desired and undesired areas without increasing physical system complexity
2Ease of operation
If a fixed beam pattern is used, then the implementation is straightforward, but the difference in sound pressure between desired and undesired areas is reduced due to interference from reflected waves
Solution Approach 1:
The patent implements periodic action by updating the beam pattern at regular time intervals based on the impulse response characteristics of the reproduction space. This periodic update allows the system to counteract interference from reflected waves that arrive at different times, maintaining effective sound pressure differences without complicating the implementation process
3Device complexity
If conventional array speaker systems use fixed beam patterns, then the system is simple to implement, but noise pollution cannot be effectively minimized and sound cannot be focused on specific areas
Solution Approach 1:
The patent uses dynamics to create time-variant beam patterns that adapt to the reproduction space characteristics. By periodically updating the beam pattern based on impulse response measurements, the system can effectively focus sound on specific areas and minimize noise pollution in undesired areas without requiring a more complex system architecture
4Manufacturing precision
If a time-variant beam pattern is generated with distance-dependent attenuation, then sound focusing performance is enhanced and noise pollution is reduced, but the system complexity increases
Solution Approach 1:
The patent applies parameter changes by modifying the beam pattern parameters over time based on distance-dependent attenuation characteristics. The system periodically updates beam pattern parameters such as attenuation rates and phase differences according to the impulse response of the reproduction space, achieving enhanced sound focusing performance through parameter adaptation rather than structural 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 enhances sound focusing performance by minimizing peaks and troughs in the frequency response, ensuring high sound pressure in desired areas and low pressure in quiet areas, thereby improving sound quality and reducing noise pollution without increasing the number or size of speakers.
Implementation Method 1
convolute the generated beam pattern with an input sound source signal to generate an acoustic signal through the convolution
Implementation Method 2
a speaker array configured to output the multi-channel signal
Data Source
AI summary
An apparatus for generating directional sound is provided. By using a time-variant beam pattern, the apparatus may generate constant direct waves in a listening area and may vary reflected waves followed by the direct waves according to time. The apparatus may convolute the time-variant beam pattern with a sound signal, may process an acoustic signal, which may be obtained through convolution, into a multi-channel signal, and may amplify and output the multi-channel signal.