Acoustic Filter Control for Directional Voice Pressure Shaping
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Solution Overview
Problem
Existing acoustic systems struggle to selectively transmit sound in specific directions while minimizing acoustic power in other areas, leading to unwanted noise for individuals who do not require guidance or conversation.
Innovation Solution
An acoustic control apparatus that combines sound increase control and acoustic power minimization control using multiple speakers, employing acoustic filter coefficients to direct sound to a specific area and minimize sound in others, achieved by dividing speakers into groups and applying phase and gain adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If acoustic control is applied to transmit voice in specific directions, then voice transmission is improved in desired areas, but voice pressure becomes insufficient in other areas where it is still needed
Solution Approach 1:
The patent divides the acoustic space into multiple control regions (first sound increase control area, second sound increase control area, and sound decrease control area) and applies different acoustic filter coefficients to each region. This segmentation allows independent optimization of voice transmission in each area, resolving the contradiction between directional control and overall voice pressure consistency.
Solution Approach 2:
The patent applies the principle of local quality by setting different acoustic filter coefficients for different spatial regions. The first and second sound increase control areas receive coefficients that amplify voice pressure locally, while the sound decrease control area receives coefficients that suppress voice pressure. This local differentiation enables precise control of voice transmission characteristics in each region without affecting others.
2Object-affected harmful factors
If multiple speakers are used to control sound distribution, then sound directionality is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple speakers (first plurality and second plurality) into a unified acoustic control system that operates under a single control device. The control device calculates and applies acoustic filter coefficients to all speakers collectively, merging their functions to achieve coordinated sound distribution across multiple control areas. This merging approach maintains sound directionality while managing system complexity through centralized control.
3Measurement precision
If acoustic filter coefficients are applied to each speaker individually, then sound control precision is improved, but computational load increases
Solution Approach 1:
The patent implements a universal acoustic filter coefficient calculation approach where the control device computes coefficients that serve multiple functions simultaneously. The same control device and calculation methodology are used to control all speakers across all control areas, making the system multi-functional. This universal approach maintains sound control precision by applying appropriate coefficients to each speaker while reducing computational overhead through code reuse and unified processing.
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
The apparatus effectively increases sound pressure in desired directions while significantly reducing acoustic power in undesired areas, enhancing sound transmission control and system miniaturization.
Implementation Method 1
The processor applies the calculated acoustic filter coefficients to an input voice signal, and branch a voice signal to which a common acoustic filter coefficient is applied, into at least two of the sound sources
Implementation Method 2
combines sound increase control and acoustic power minimization control using multiple speakers, employing acoustic filter coefficients to direct sound to a specific area and minimize sound in others
Data Source
AI summary
According to one embodiment, an acoustic control apparatus includes a processor. The processor calculates acoustic filter coefficients which are smaller in number than a plurality of sound sources, based on a first relational expression between acoustic filters applied to a voice signal containing information of voice reproduced by each of the sound sources, which is based on a sound increase control law that increases voice pressure at a sound increase control point by voices reproduced by the sound sources, and a second relational expression between the acoustic filters, which is based on an acoustic power minimization control law that minimizes acoustic power for voices reproduced by the sound sources. The processor applies the calculated acoustic filter coefficients to an input voice signal, and branch a voice signal to which a common acoustic filter coefficient is applied, into at least two of the sound sources.