In-Situ Acoustic Attenuation Measurement System
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Solution Overview
Problem
Existing methods for measuring in-situ acoustic attenuation of hearing protection devices lack reliability and reproducibility, often requiring modifications to the standard devices and providing variable test conditions.
Innovation Solution
A system comprising a hearing protection device with a microphone oriented towards the ear canal and a cup-like measuring device creating a closed space, using a loudspeaker to provide a test sound and a microphone to capture sound levels within this space, ensuring well-defined test conditions and minimal modifications to the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing methods for measuring in-situ acoustic attenuation are used, then measurements can be performed, but the measurements lack reliability and reproducibility
Solution Approach 1:
The measuring device is segmented into functionally independent components: a cup-like structure for creating the closed space, a loudspeaker for generating test sounds, and a microphone for capturing sound levels. This segmentation allows each component to be optimized for its specific function, improving overall measurement reliability and reproducibility
Solution Approach 2:
The cup-like measuring device acts as an intermediary that creates a controlled closed space between the loudspeaker and the hearing protection device. This intermediary structure standardizes the acoustic environment, eliminating variable test conditions and improving measurement consistency
2Measurement precision
If standard hearing protection devices are modified for in-situ measurement, then measurements can be performed, but the modifications increase device complexity
Solution Approach 1:
The measurement system is divided into the hearing protection device and a separate cup-like measuring device. This segmentation allows the hearing protection device to remain standard and unmodified, while all measurement functionality is contained in the external measuring device, thus minimizing modifications to the hearing protection device
Solution Approach 2:
The cup-like measuring device is designed as a universal measurement platform that can be used with any standard hearing protection device. By concentrating all measurement-specific components (loudspeaker, microphone, closed space structure) in the measuring device, the system achieves multi-functionality without modifying the hearing protection device itself
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 approach provides reliable and reproducible in-situ measurements of acoustic attenuation by ensuring consistent test conditions and reducing the need for modifications to standard hearing protection devices.
Implementation Method 1
a loudspeaker for providing a test sound to the closed space
Implementation Method 2
a first microphone oriented towards the ear canal for picking up a sound level inside the ear canal
Implementation Method 3
a second microphone oriented towards ambience for picking up a sound level in the environment
Implementation Method 4
measuring the acoustic attenuation provided by a hearing protection device
Data Source
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AI summary
The invention relates to a method for measuring in-situ the acoustic attenuation obtained by a hearing protection device (10) worn by a user, comprising: positioning the hearing protection device (10) comprising a microphone (16) oriented towards the user's ear canal (14) at the user's ear; positioning a cup-like measuring device (26) comprising a loudspeaker (32) oriented towards to user's ear and a microphone (34) oriented towards to user's ear at the user's ear in such a manner that a closed space (28) surrounding the hearing protection device is created by the measuring device (26); providing a test signal via the loudspeaker (32), capturing audio signals representative of the level of the test signal in the closed space (28) by the microphone (34) of the measuring device (26) and capturing audio signals representative of the level of the test signal in the user's ear canal (14) by the microphone (16) of the hearing protection device (10); processing the audio signals captured by the microphone (34) of the measuring device (26) and the audio signals captured by the microphone (16) of the hearing protection device (10) and estimating the attenuation provided by the hearing protection device (10) from the processed audio signals.