Hearing Aid Acoustic Feedback and Maintenance Design

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Solution Overview

Problem

Hearing aids designed for deep insertion into the auditory canal face issues with acoustic feedback and difficulty in removal for cleaning and maintenance, requiring innovative solutions to prevent whistle generation and ensure easy extraction.

Innovation Solution

The hearing aid features a device housing with a sealing fitting body, a pull member for easy removal, and acoustic separation between the loudspeaker and microphone, along with a programmable sound processing device for adjustment without disassembly, and a battery chamber with ventilation to prevent feedback and enhance battery lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the hearing aid is designed for deep insertion into the auditory canal, then the acoustic feedback is reduced, but the device becomes difficult to remove for cleaning and maintenance

Engineering Contradiction:
Improveacoustic feedbackVSAvoidremoval for maintenance
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The device is divided into two main segments: a removable device housing containing electronic components and a fitting body that remains in the ear. The device housing can be detached from the fitting body for cleaning and maintenance while leaving the fitting body in place, thus facilitating maintenance while maintaining deep insertion benefits

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A pull member is introduced as an intermediary element that extends from the device housing through the fitting body to the external environment. This pull member serves as a mediator that enables easy removal of the device housing from the fitting body without requiring the user to reach deep into the auditory canal

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of moving object

If the distance between microphone and sound-emitting opening is reduced, then the hearing aid fits better in the auditory canal, but acoustic feedback increases

Engineering Contradiction:
Improvedistance between microphone and sound-emitting openingVSAvoidacoustic feedback
Core Design Contradiction:
Length of moving objectVSObject-generated harmful factors

Solution Approach 1:

The internal space is segmented into separate acoustic zones using acoustic barriers and partitions. The microphone area and loudspeaker area are acoustically isolated from each other, preventing sound from the loudspeaker from reaching the microphone even though the physical distance is short

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Acoustic barriers and sealing elements are introduced as intermediary structures between the microphone and the sound-emitting opening. These barriers prevent direct acoustic coupling while allowing the device to maintain a compact form factor suitable for deep insertion

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the device housing is sealed to prevent feedback, then acoustic feedback is reduced, but battery ventilation is compromised

Engineering Contradiction:
Improveacoustic feedbackVSAvoidbattery lifespan
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The internal volume is segmented into separate acoustic compartments. The battery chamber is acoustically isolated from the sound-emitting path using partitions and barriers, allowing the housing to be sealed against feedback while maintaining ventilation pathways for the battery

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the housing have different acoustic properties. The areas surrounding the microphone and sound-emitting opening are heavily sealed, while the battery chamber region includes controlled ventilation openings that allow air flow for battery cooling and gas exchange without creating acoustic feedback paths

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 design significantly reduces acoustic feedback, facilitates easy removal and maintenance, allows for in-ear adjustment of sound processing, and extends battery life by preventing sound penetration into the battery chamber.

Implementation Method 1

an outer wall of the device housing lies sealingly against an inner wall of said cavity

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

the device housing is at least partly accommodated in a fitting body having an outer wall which is configured to lie sealingly within said auditory canal of the user

Methodology Applied
Scientific EffectSealing:

Implementation Method 3

a loudspeaker which is in open communication with a sound-emitting opening of the hearing aid

Methodology Applied
Scientific EffectSound transmission: Sound

Implementation Method 4

a microphone on a proximal side for receiving sound

Methodology Applied
Scientific EffectSound reception: Sound

Implementation Method 5

a sound processing device for reproducing said sound by the loudspeaker in at least partly processed manner

Methodology Applied
Scientific EffectSignal processing:

Implementation Method 6

a battery chamber for receiving a battery therein

Methodology Applied
Scientific EffectBattery energy conversion: Battery (electricity)

Data Source

PatentEP2827611B1Hearing aid
Publication Date: 2019.11.20 EXSILENT RES BV
  • EP2827611B1 patent drawingFigure 1~2
  • EP2827611B1 patent drawingFigure 3~4
  • EP2827611B1 patent drawingFigure 5~6

AI summary

A hearing aid comprises a microphone on a proximal side of a device housing and a loudspeaker which via a transmission channel is in open communication with a sound-emitting opening of the device. A sound processing device serves to generate sound received by the microphone to the loudspeaker in amplified form. The device housing is provided on a distal side with an optionally sealed battery chamber for receiving a battery therein. The transmission channel is at least almost wholly separated from the microphone acoustically in order to prevent acoustic feedback. The battery chamber comprises ventilation means for the purpose of increasing the lifespan of the battery.