Microphone Positioning Using Audio Time Difference
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Solution Overview
Problem
Existing audio systems with a stereo speaker and microphone cannot accurately measure the two-dimensional position of the microphone without synchronization, requiring at least three transmission devices.
Innovation Solution
An information processing device and method that uses an audio reception unit to receive a spreading code signal from two audio output blocks at known positions, calculating the microphone's position based on the arrival time difference distance between the signals received from these blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a stereo speaker system with two speakers and a microphone is used, then the device complexity is reduced, but the measurement precision of two-dimensional position cannot be obtained
Solution Approach 1:
The patent transforms the one-dimensional distance measurement problem into a two-dimensional position measurement problem by utilizing the spatial arrangement of two speakers. By measuring the arrival time difference of audio signals from two known positions (speakers), the system calculates the microphone's position in two dimensions without requiring three or more transmission devices. This dimensional transformation enables 2D positioning with only two speakers.
2Measurement precision
If at least three transmission devices are used to obtain two-dimensional position, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent achieves two-dimensional positioning with only two speakers by exploiting the temporal dimension (arrival time difference) rather than requiring additional spatial transmitters. The system calculates position based on the time difference of arrival of audio signals from two known speaker positions, effectively using time as an additional dimension to enable 2D positioning without adding more physical transmission devices.
3Measurement precision
If time synchronization between reception device and transmission device is ensured, then the measurement precision is improved, but the ease of operation deteriorates
Solution Approach 1:
The patent employs cross-correlation processing to automatically determine the time difference of arrival between audio signals from two speakers. The system correlates the received audio signal with stored reference signals from each speaker to identify arrival times without requiring external synchronization mechanisms. This feedback-based approach eliminates the need for manual time synchronization while maintaining measurement precision.
Solution Approach 2:
The patent replaces mechanical/electronic synchronization systems with an acoustic-based time difference measurement approach. Instead of using synchronized clocks or complex timing protocols, the system uses the natural propagation of audio signals and measures the time difference directly through cross-correlation, simplifying the operational requirements while maintaining positioning accuracy.
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 accurate two-dimensional position measurement of the microphone in an audio system using a stereo speaker and microphone, improving positional accuracy and reducing the need for multiple transmission devices.
Implementation Method 1
an audio reception unit that receives an audio signal including a spreading code signal obtained by performing spread spectrum modulation on a spreading code, the audio signal being output from two audio output blocks existing at known positions
Implementation Method 2
a position calculation unit that calculates a position of the audio reception unit on the basis of an arrival time difference distance that is a difference between distances identified from an arrival time that is a time until the audio signals of the two audio output blocks arrive at the audio reception unit and are received
Data Source
AI summary
There is provided an information processing device, an information processing method, and a program that enable a system including two speakers and one microphone to measure a position of the microphone. An audio reception block receives an audio signal including a spreading code signal obtained by performing spread spectrum modulation on a spreading code, the audio signal being output from two audio output blocks existing at a known positions, and calculates a position of an audio reception unit on the basis of an arrival time difference distance that is a difference between distances to the two audio output blocks based on an arrival time at which a peak of cross-correlation is detected. The present invention can be applied to a game controller or an HMD.