Microphone Test Device With Separate Acoustic Cavities
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Solution Overview
Problem
Existing microphone testing devices lack effective methods to ensure accurate and decoupled measurements for testing microphones, leading to potential interference and incorrect assessments of microphone functionality.
Innovation Solution
A test device with separate test and reference cavities, where the test tone is emitted by a test loudspeaker and captured by both the microphone under test and a reference microphone, allowing for independent evaluation and minimizing mutual influence, along with a compact design that positions the reference microphone opposite the test loudspeaker, ensuring accurate and comparable signal capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the reference microphone is placed in the same cavity as the test loudspeaker and microphone under test, then the device structure is simplified, but measurement precision deteriorates due to acoustic interference between the test tone and reference signal
Solution Approach 1:
The patent divides the acoustic measurement system into two separate cavities: a test cavity for the microphone under test and a reference cavity for the reference microphone. This segmentation isolates the acoustic paths, preventing interference between the test tone and reference signal while maintaining a compact overall structure through spatial separation of functional zones.
2Volume of moving object
If the reference microphone is positioned close to the test loudspeaker, then the device becomes more compact, but harmful acoustic interference increases affecting measurement accuracy
Solution Approach 1:
The patent introduces separate cavities as intermediary structures between the test loudspeaker and the reference microphone. These cavities act as acoustic isolators that prevent direct coupling of sound waves, thereby eliminating harmful acoustic interference while allowing the reference microphone to be positioned in close proximity to the test loudspeaker for compact device volume.
3Device complexity
If the microphone under test and reference microphone share the same acoustic space, then the testing device is simpler to construct, but reliability of test results deteriorates due to cross-contamination of signals
Solution Approach 1:
The patent segments the acoustic measurement environment into distinct test and reference cavities. This segmentation ensures that the test tone captured by the microphone under test and the reference signal captured by the reference microphone are acoustically isolated, preventing cross-contamination of signals and ensuring reliable test results while maintaining relatively simple device construction.
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
This configuration enables precise evaluation of microphone functionality by ensuring that the test tone is accurately captured and compared, reducing interference and allowing for the identification of distorted or non-functional microphones, thereby improving the reliability of the testing process.
Implementation Method 1
at least one test loudspeaker for generating at least one test tone
Implementation Method 2
the test loudspeaker can emit the test tone into the test cavity
Implementation Method 3
the microphone under test can be acoustically coupled to the test cavity... the microphone under test can thus be coupled to the test cavity
Implementation Method 4
at least one reference microphone for determining a reference signal of the test tone emitted by the test loudspeaker
Data Source
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AI summary
The invention relates to a test device (1) for testing a microphone (2) with at least one test loudspeaker (3) for generating at least one test tone (4), with at least one test cavity (5) into which the test tone (4) can be emitted, with at least one recording area (7) for receiving the microphone (2) to be tested, which is designed in such a way that the microphone (2) to be tested can be acoustically coupled to the test cavity (5), and with at least one reference microphone (8) for determining a reference signal of the test tone (4) emitted by the test loudspeaker (3).According to the invention, the test device (1) has a reference cavity (13) separate from the test cavity (5), into which the test tone (4) can also be emitted and with which the reference microphone (8) is acoustically coupled for determining the reference signal, and/or that the recording area (7) is arranged on a first side (6) of the test loudspeaker (3) and the reference microphone (8) is arranged on a second side (9) of the test loudspeaker (3) opposite the first side (6).