Hearing Device Earpiece Microstructures for Cerumen and Retention

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Solution Overview

Problem

Existing earpieces for hearing devices suffer from cerumen ingress and clogging of acoustic ports due to displacement and migration, leading to hearing assistance loss and poor retention during head movements.

Innovation Solution

The earpiece features micro structured surfaces on the outer and inner surfaces to enhance cerumen removal, improve retention, and reduce migration, manufactured via 3D printing or molding techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a smooth earpiece surface is used, then the earpiece is easy to manufacture and biocompatible, but cerumen ingress and clogging of acoustic ports occurs

Engineering Contradiction:
Improveease of manufactureVSAvoidacoustic port clogging
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies micro-structured features (such as micro-protrusions or textured patterns) specifically to the outer surface of the earpiece that contacts the ear canal wall, while keeping the inner surface and acoustic ports smooth. This localized application of surface structuring prevents cerumen accumulation at the contact interface without affecting the smoothness required for acoustic port clearance and manufacturing simplicity.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If a dome earpiece is used, then the earpiece is flexible and easy to insert, but retention in the ear canal is poor and the earpiece moves during head movements

Engineering Contradiction:
Improveease of insertionVSAvoidretention in ear canal
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces asymmetric micro-structured features on the outer surface of the dome earpiece, creating directional friction characteristics that enhance retention during head movements while maintaining ease of insertion. The asymmetric pattern provides mechanical interlocking with the ear canal wall that prevents the earpiece from moving outward during acceleration.

Inventive Principle:
Principle #4Asymmetry

3Ease of repair

If the outer surface is made smooth, then the earpiece is easy to clean, but cerumen and contaminants accumulate and migrate into acoustic ports

Engineering Contradiction:
Improveease of cleaningVSAvoidcerumen migration
Core Design Contradiction:
Ease of repairVSObject-generated harmful factors

Solution Approach 1:

The patent localizes the micro-structured features to specific regions of the outer surface that are in contact with the ear canal wall during insertion and wear, while leaving other areas smooth for ease of cleaning. The structured regions trap cerumen and contaminants at the interface, preventing their migration into acoustic ports, while smooth areas remain accessible for cleaning.

Inventive Principle:
Principle #3Local quality

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

The micro structured features effectively remove cerumen and other contaminants, enhance retention, and maintain acoustic sealing, reducing clogging and improving wearing comfort and sound dampening.

Implementation Method 1

the micro structured features have a height or depth in a range from 10 μm to 150 μm and/or a width in a range from 10 μm to 150 μm... These dimensions of the micro structured features on the outside of the earpiece have shown improved capability to remove cerumen, dead skin cells, sebum or sweat from the ear canal

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the micro structured features effectively remove cerumen and other contaminants... enhance retention... improve wearing comfort

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

the micro structured features enhance retention... Compared to a custom earpiece, the retention of a dome in the ear canal may be considerably worse. Consequently, the dome may move out of the ear canal due to inertial forces associated with head movements

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

The earpiece is made of or comprises a compliant or soft material, preferably silicone... maintain acoustic sealing... improve wearing comfort

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4601320A1Earpiece for a hearing device
Publication Date: 2025.08.13 SONOVA AG
  • EP4601320A1 patent drawingFigure 1~2
  • EP4601320A1 patent drawingFigure 3~5
  • EP4601320A1 patent drawing

AI summary

The invention relates to an earpiece (1) configured to be mounted to a hearing device, the earpiece (1) having an outer surface and an inner surface, at least a part of the outer surface intended to contact an ear canal wall of a user's ear when being inserted in the ear canal comprising micro structured features (3).