Speaker Volume Adjustment Using Direct and Indirect Sound
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Solution Overview
Problem
Existing volume adjustment devices face challenges in determining the optimal microphone installation position and necessary measurements to accurately adjust sound volumes, considering both direct and indirect sounds in a room environment.
Innovation Solution
A volume adjustment device comprising a microphone, a speaker, and a signal processing unit that outputs a measurement sound to measure a first impulse response, allowing for volume adjustment based on the levels of direct and indirect sound components, enabling appropriate volume setting regardless of microphone placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the microphone is installed at a fixed position to measure sound pressure, then the volume adjustment can be performed, but the measurement accuracy deteriorates when the microphone position is not optimal
Solution Approach 1:
The patent segments the impulse response into direct sound components and indirect sound components (reflected sound, reverberant sound) based on time characteristics. By separating these components, the system can independently analyze and adjust for each type of sound, enabling accurate volume measurement regardless of microphone position.
Solution Approach 2:
The patent dynamically adjusts the volume setting based on the measured levels of direct sound and indirect sound components. Instead of using a fixed volume adjustment method, the system calculates appropriate volume levels by considering the temporal characteristics and energy distribution of different sound components, adapting to various microphone positions and room acoustic conditions.
2Measurement precision
If the volume is adjusted considering only direct sound, then the adjustment process is simplified, but the volume accuracy deteriorates due to ignoring indirect sound
Solution Approach 1:
The patent segments the impulse response into direct sound components and indirect sound components based on time characteristics. This segmentation allows the system to separately measure and analyze direct sound and indirect sound levels, enabling accurate volume adjustment that considers both sound types without requiring complex measurement procedures.
Solution Approach 2:
The patent uses feedback by measuring the actual sound levels of direct and indirect components in the room and using this information to calculate appropriate volume adjustments. The system continuously monitors the acoustic environment and adjusts volume settings based on the measured characteristics, ensuring accurate volume control while accounting for room acoustics.
3Measurement precision
If multiple measurement positions are used to determine optimal volume, then the volume adjustment accuracy is improved, but the measurement time increases
Solution Approach 1:
The patent dynamically processes the impulse response to extract direct and indirect sound components based on their temporal characteristics. By analyzing the time-domain structure of the impulse response, the system can determine appropriate volume adjustments from a single measurement position, eliminating the need for multiple position measurements while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary analysis of the impulse response to separate direct and indirect sound components before conducting volume adjustment. By pre-processing the acoustic data to identify and characterize different sound components, the system prepares the necessary information for accurate volume calculation from a single measurement, avoiding the need for repeated measurements at different positions.
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 solution effectively adjusts sound volumes to an appropriate level by accounting for both direct and indirect sound components, ensuring optimal acoustic conditions regardless of microphone position, thereby improving sound reproduction quality.
Implementation Method 1
The sound that reaches a listening position after being output from the speaker includes not only a direct sound but also an indirect sound such as a reflected sound and a reverberant sound in a room
Data Source
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AI summary
A volume adjustment device includes a microphone, a speaker, and a signal processing unit. The at least one signal processing unit includes at least one processor and at least one memory. The signal processing unit is configured to output a measurement sound from the speaker. The signal processing unit is also configured to measure a first impulse response with the microphone. The signal processing unit is also configured to adjust a volume of the measurement sound output from the speaker based on a direct sound component of the first impulse response and an indirect sound component of the first impulse response.