Dual Speaker Array Sound Field Cancellation Depth Control
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Solution Overview
Problem
Conventional methods for local sound field silencing, such as using parametric speakers or linear speaker arrays, face difficulties in controlling the silenced area in the depth direction and are limited by frequency bands, making it challenging to achieve precise sound suppression at desired positions.
Innovation Solution
A locally silenced sound field forming apparatus comprising two speaker arrays, where one array generates a sound field and the other cancels it, using acquisition units to determine distances and drive signal generation units to produce inverted phase signals for precise sound field cancellation, allowing control of the silenced area in the depth direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If directivity control using parametric speaker or linear speaker array is used for local silencing, then the silenced area can be moved in the left and right directions, but it is difficult to control the silenced area in the depth direction
Solution Approach 1:
The patent transitions from controlling silenced area position only in the horizontal direction (left-right) to enabling control in three-dimensional space including the depth direction. This is achieved by using multiple speaker arrays positioned at different locations and combining their sound fields through digital signal processing to create silenced areas at arbitrary positions in space, not just laterally adjacent to a single speaker array.
Solution Approach 2:
The patent divides the sound field control function across multiple speaker arrays rather than relying on a single array. By segmenting the acoustic space and using multiple distributed speaker arrays, the system can independently control silenced areas in different spatial regions, enabling depth direction control that was impossible with a single linear array.
2Measurement precision
If parametric speaker is used for local silencing, then directivity control is achieved, but frequency bands available for reproduced sounds are limited
Solution Approach 1:
The patent combines the outputs of multiple speaker arrays through digital signal processing to achieve both precise directivity control and extended frequency response. By merging the acoustic fields from multiple sources with different frequency characteristics, the system maintains the directional control precision of parametric speakers while overcoming their frequency limitations through constructive and destructive interference patterns.
Solution Approach 2:
The system creates a multi-functional audio control platform that can simultaneously achieve precise directional sound field control and reproduce sounds across a wide frequency range. The multiple speaker arrays serve multiple purposes: individual arrays can handle specific frequency ranges while collectively providing omnidirectional control capabilities and extended bandwidth beyond what any single parametric speaker could achieve.
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
Enables the formation of a silenced area at a desired position in the depth direction while maintaining audible sound fields in front and rear areas, providing flexible control over the silenced region.
Implementation Method 1
a second speaker array arranged at a position different from the position of the first speaker array and that outputs a sound on the basis of a second speaker drive signal to form a sound field that cancels the predetermined sound field
Data Source
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AI summary
The present technology relates to a locally silenced sound field forming apparatus and method, and a program capable of controlling a silenced area in a depth direction. The locally silenced sound field forming apparatus includes: a first speaker array that outputs a sound on the basis of a first speaker drive signal to form a predetermined sound field; and a second speaker array arranged at a position different from the position of the first speaker array and that outputs a sound on the basis of a second speaker drive signal to form a sound field that cancels the predetermined sound field. The present technology can be applied to a locally silenced sound field forming apparatus.