System and method for estimating an acoustic attenuation of a hearing protection device
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Publication Number
US-12140472-B2
Publication Date
2024-11-12
Expiration Date
Abstract
There is provided a system for estimating a total acoustic attenuation of a hearing protection device including an interface at a distal end and a sound canal extending from the interface to a sound opening at a medial end of the hearing protection device. The system comprises: a measurement unit including a loudspeaker and a microphone and being attachable to the interface in such a manner that, when the hearing protection device is worn in an ear canal of a user, the loudspeaker and the microphone are in acoustic communication, via the sound canal of the hearing protection device; a control unit configured to provide the loudspeaker with test audio signals to generate test sounds in the occluded ear canal volume and to receive test response audio signals captured by the microphone from the test sounds; and an evaluation unit configured to estimate a leakage acoustic impedance.
Core Innovation
The invention provides a system and method for estimating a total acoustic attenuation of a hearing protection device of a given type. The hearing protection device includes an interface at a distal end and a sound canal extending to a sound opening at a medial end, and the system comprises a measurement unit and an evaluation unit. The measurement unit includes a loudspeaker and a microphone and is attachable to the interface so that, when the device is worn in an ear canal, the loudspeaker and the microphone are in acoustic communication with a residual ear canal volume occluded by the hearing protection device. Test sounds are generated in the occluded ear canal volume and test response audio signals are captured by the microphone.
The evaluation unit estimates a leakage acoustic impedance of a leakage path between a wall of the ear canal and the hearing protection device. The leakage path connects the residual ear canal volume to an outside of the ear canal, and the leakage acoustic impedance is estimated from the received test response audio signals. The evaluation unit also estimates an occluded ear acoustic impedance. Using the estimated leakage acoustic impedance and the estimated occluded ear acoustic impedance, the evaluation unit estimates the total acoustic attenuation provided by the hearing protection device.
The total acoustic attenuation estimation takes into account predetermined statistical data related to acoustic attenuation provided by the given type of hearing protection device. The predetermined statistical data includes REAT values measured for other users for the type of hearing protection device when being used with a detachable acoustic filter. In this way, the system combines acoustical impedance estimates with type-related statistical attenuation information to produce an estimated total acoustic attenuation.
Claims Coverage
Two independent claims are provided, covering both a system and a method. The independent claim set specifies measurement-unit attachment at the hearing-protection device interface, estimation of leakage and occluded-ear acoustic impedances from microphone response to test sounds, and calculation of total acoustic attenuation using predetermined statistical data that includes REAT values measured for other users when used with a detachable acoustic filter.
Worn-device test sound measurement using detachable loudspeaker and microphone
A measurement unit including a loudspeaker and a microphone is attachable to an interface at a distal end such that, when the hearing protection device is worn in an ear canal, the loudspeaker and the microphone are in acoustic communication, via the sound canal, with a residual ear canal volume occluded by the hearing protection device to generate test sounds and capture test response audio signals.
Leakage acoustic impedance estimation from microphone response
An evaluation unit estimates a leakage acoustic impedance of a leakage path between a wall of the ear canal and the hearing protection device from the received test response audio signals, where the leakage path connects the residual ear canal volume to an outside of the ear canal.
Occluded ear acoustic impedance estimation
The evaluation unit estimates an occluded ear acoustic impedance based on the received test response audio signals in combination with the measurement configuration described for the worn hearing protection device.
Total acoustic attenuation estimation using leakage/occluded impedances and REAT statistical data
The evaluation unit estimates the total acoustic attenuation provided by the hearing protection device using the estimated leakage acoustic impedance, the estimated occluded ear acoustic impedance, and predetermined statistical data related to acoustic attenuation provided by the given type of hearing protection device, the predetermined statistical data including REAT values measured for other users for the type of hearing protection device when being used with a detachable acoustic filter.
Method steps for impedance-based total attenuation estimation using detachable acoustic filter REAT
A method of estimating a total acoustic attenuation attaches a measurement unit including a loudspeaker and a microphone to the interface, inserts the hearing protection device into an ear canal so the residual ear canal volume is occluded, provides test audio signals to generate test sounds in the occluded ear canal volume, receives test response audio signals, estimates a leakage acoustic impedance of a leakage path from the response audio signals, and estimates total acoustic attenuation from the estimated leakage acoustic impedance taking into account predetermined statistical data including REAT values measured for other users for the type when used with a detachable acoustic filter.
Overall, the independent claims converge on a detachable measurement unit worn with the hearing protection device, impedance estimation (leakage and occluded ear, with total attenuation computed accordingly), and use of predetermined REAT statistical data associated with detachable acoustic filters.
Stated Advantages
Not explicitly described in patent.
Documented Applications
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