Earphone Groove and Ear Tip Pressure Equalization Path

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Solution Overview

Problem

Devices that block the ear canal, such as headphones and hearing aids, often cause an amplification of low-frequency sounds due to the occlusion effect, which can be uncomfortable for users, and existing solutions like pressure equalization ports compromise noise isolation.

Innovation Solution

An earphone design featuring a groove on the outer surface of the earphone body that forms a hollow tube with the flexible ear tip, providing an external pressure equalization path without adding volume or compromising noise isolation, with specific dimensions and acoustic impedance characteristics to manage frequency response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a pressure equalization port is provided as a hole or tube through the ear tip or inner bud, then the occlusion effect is relieved, but noise isolation is compromised

Engineering Contradiction:
Improveocclusion effectVSAvoidnoise isolation
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The groove is nested within the outer surface of the earphone body, forming a hollow tube structure when the ear tip is fitted. This nested design allows the PEQ port to be integrated within the existing structure without adding external volume or compromising the sealing interface between the ear tip and earphone body, thereby maintaining noise isolation while relieving the occlusion effect.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The groove extends along the length of the earphone body in a linear dimension, creating a tunnel-like PEQ port that connects the front volume to the external environment. This dimensional approach allows the PEQ function to be achieved without adding radial or volumetric complexity, preserving the compact form factor and noise isolation properties.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If a pressure equalization port is added to the earphone, then the occlusion effect is relieved, but the volume of the earphone increases

Engineering Contradiction:
Improveocclusion effectVSAvoidearphone volume
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The groove is nested within the outer surface of the earphone body, utilizing the existing structural volume rather than adding to it. This nested design allows the PEQ port to be integrated within the existing structure without adding external volume, thereby maintaining the compact form factor while relieving the occlusion effect.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The PEQ port structure is merged with the outer surface of the earphone body by forming a groove within it. This merging approach combines the PEQ function with the existing housing structure, eliminating the need for separate PEQ components and avoiding additional volume increase.

Inventive Principle:
Principle #5Merging (Combining)

3Object-generated harmful factors

If a groove is formed on the outer surface of the earphone body to create a PEQ port, then noise isolation is maintained, but manufacturing precision requirements increase

Engineering Contradiction:
Improvenoise isolationVSAvoidgroove dimensions
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The ear tip is made of flexible material that can deform to accommodate variations in the groove dimensions. This flexibility compensates for manufacturing tolerances in the groove, ensuring that the PEQ port functions correctly and maintains noise isolation without requiring extremely tight manufacturing precision.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The groove dimensions are optimized to provide adequate PEQ function while remaining within practical manufacturing tolerances. By carefully selecting the groove width, depth, and length parameters, the design achieves a balance between manufacturing feasibility and acoustic performance, avoiding overly stringent precision requirements.

Inventive Principle:
Principle #35Parameter changes

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

Effectively relieves the occlusion effect while maintaining consistent acoustic properties and noise isolation across frequencies, preventing external pressure from closing the port and ensuring reliable operation.

Implementation Method 1

pressure equalization path... providing an external pressure equalization path... Acoustically couples the front volume with an environment external to the earphone

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 2

An ear tip is composed of flexible material and having an inner surface corresponding in shape to at least a portion of the outer surface of the earphone body... configured to contact the ear and seal the ear canal

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3625970B1Headphones with external pressure equalization path
Publication Date: 2022.04.20 BOSE CORP
  • EP3625970B1 patent drawingFigure 1
  • EP3625970B1 patent drawingFigure 2
  • EP3625970B1 patent drawingFigure 3

AI summary

An earphone includes a housing enclosing an acoustic transducer and having a front volume. The housing includes a nozzle that extends the front volume to at least an entrance of a wearer's ear canal, and a groove in an outer surface of the housing, extending at least along a length of the nozzle. A flexible ear tip is configured to attach to the housing. When the flexible ear tip attaches to the housing, the groove and a portion of an inner surface of the ear tip together form a port that acoustically couples the front volume with an environment external to the earphone.