Passive non-linear acoustic filters
Inventors
Lawrence, Tyson • Fowler, Brian • Saunders, James F. • Dunn, Charles
Assignees
Publication Number
US-12186156-B2
Publication Date
2025-01-07
Expiration Date
2041-09-13
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Earplugs that have enhanced performance in protecting the user from high noise levels without impeding auditory awareness are described. The earplugs comprise a housing and a non-linear acoustic filter, wherein the non-linear acoustic filter can comprise a bulb. The earplugs are designed to be compatible with other types of headwear, e.g., headphones and helmets.
Core Innovation
The invention provides earplugs comprising a housing and a non-linear acoustic filter, in which the non-linear acoustic filter can include a bulb, and the filter may be constructed from or include one or more sets of individual microspheres surrounded by a mesh. The design allows the earplug to occupy the inner part of the ear canal, with the housing extending generally linearly along the earplug's longitudinal axis and defining a bore. The non-linear acoustic filter also extends along this axis, featuring a proximal end adjacent to the eardrum, a distal end adjacent to the external orifice, and a middle section between these ends.
The problem addressed by this invention is the need for improved earplugs or earmuffs that maintain situational awareness while providing significant hearing protection against impulsive noise sources. Conventional pass-through or hear-through earplugs and earmuffs, including those relying on electronic systems or linear filters, generally impair auditory awareness and localization due to near-closed paths and interference with the head-related transfer function caused by insertion in the pinna and outer ear canal.
The disclosed earplugs aim to solve this issue by employing a passive, non-linear acoustic filter that attenuates high-amplitude or impulsive noises without significantly impeding the transmission of softer sounds, thus preserving auditory awareness and localization capabilities. The non-linear acoustic filter may be designed using various geometries or components such as end caps with holes, microspheres, helical filters, mufflers, Helmholtz resonators, Tesla valves, or phononic crystals. Furthermore, the earplugs are designed to be compatible with other types of headwear, including headphones and helmets.
Claims Coverage
The patent contains one independent claim that introduces a primary inventive feature related to an earplug with a specific arrangement of a non-linear acoustic filter comprising microspheres surrounded by mesh.
Earplug with non-linear acoustic filter comprising microspheres surrounded by mesh
An earplug is provided that: - Includes a housing that extends generally linearly along a longitudinal axis and defines a bore. - Contains a non-linear acoustic filter extending generally linearly along the same longitudinal axis, disposed at least partially in the bore. - The non-linear acoustic filter has a proximal end adjacent to the eardrum, a distal end adjacent to the ear canal's external orifice, and a middle section between these ends. - The filter comprises one or more sets of individual microspheres that are surrounded by a mesh to keep them together. - The earplug is specifically designed to occupy the inner part of the ear canal.
The independent claim focuses on an earplug with a non-linear acoustic filter using microspheres surrounded by mesh, specifically arranged to optimize placement and function within the ear canal.
Stated Advantages
Provides enhanced protection from high noise levels without impeding auditory awareness.
Maintains nearly true hearing in the absence of loud noises and automatically attenuates louder sounds such as gunfire.
Offers near-unoccluded localization capability, thus minimizing impact on the user's situational awareness and Head Related Transfer Function.
Ensures detection, recognition, and communication abilities are not statistically different from open-ear conditions under tested scenarios.
Documented Applications
Use within or as part of earplugs providing hearing protection while maintaining auditory awareness.
Mounting within or as part of earmuffs to offer similar protection and awareness benefits.
Integration into helmets for user groups requiring both hearing protection and the ability to maintain situational awareness, including soldiers.
Interested in licensing this patent?