Acoustic Measurement Device Timing Delay Compensation

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Solution Overview

Problem

Low-cost acoustic devices often experience timing delays in signal output, leading to inconsistent signal reproduction periods, which hinders synchronous addition of measurement signals necessary for accurate impulse response measurement and transfer characteristic analysis.

Innovation Solution

A measurement device and method that utilize a processor to generate filters by measuring and processing transfer characteristics between speakers and microphones, employing convolution calculations and error correction to ensure consistent signal reproduction and synchronization, even in non-ideal environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If low-cost acoustic devices are used for impulse response measurement, then device cost is reduced, but timing delay inconsistency occurs causing measurement precision degradation

Engineering Contradiction:
Improvedevice costVSAvoidmeasurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The system performs preliminary measurement of transfer characteristics between speakers and microphones before actual audio processing. These pre-measured characteristics are stored and used to generate filters that compensate for timing delays, allowing accurate measurement without requiring expensive synchronized equipment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system measures the actual transfer characteristics (including timing delays) between speakers and microphones, uses this feedback information to generate corrective filters, and applies these filters to compensate for the measured delays. This closed-loop approach enables low-cost devices to achieve precision comparable to expensive synchronized systems

Inventive Principle:
Principle #23Feedback

2Measurement precision

If synchronous addition of measurement signals is performed to improve S/N ratio, then measurement accuracy is improved, but device complexity increases due to timing synchronization requirements

Engineering Contradiction:
ImproveS/N ratioVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system extracts and measures the transfer characteristics (including timing information) between speakers and microphones as a separate preliminary step. By removing the timing synchronization complexity from the main measurement process and handling it separately through pre-measured characteristics, the system achieves synchronous addition without requiring complex real-time synchronization hardware

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system introduces transfer characteristic measurement as an intermediary step between signal generation and analysis. This intermediate measurement process captures timing information and device characteristics, allowing subsequent processing to account for delays without requiring direct timing synchronization between all components

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3428915B1Measuring device, filter generating device, measuring method, and filter generating method
Publication Date: 2020.05.27 JVC KENWOOD CORP
  • EP3428915B1 patent drawingFigure 1
  • EP3428915B1 patent drawingFigure 2
  • EP3428915B1 patent drawingFigure 3~4

AI summary

A measurement device, a filter generation device, a measurement method and a filter generation method capable of carrying out measurement appropriately are provided. A measurement device according to this embodiment includes a peak detection unit (311) that detects positive and negative peaks included in a sound pickup signal, a sign determination unit (312) that determines a positive or negative sign based on amplitudes at the negative and positive peaks detected by the peak detection unit (311), a peak group separation unit (313) that separates a peak sequence composed of the peaks with the determined sign into a plurality of peak groups, a maximum amplitude detection unit (314) that detects a maximum amplitude in each of the plurality of peak groups, a signal cutout unit (315) that cuts out the sound pickup signal at cutout timing based on the maximum amplitude and generates a plurality of cutout signals, and a signal adding unit (316) that adds the plurality of cutout signals.