Hearing Aid Wind Shield Laminar Flow Channel

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Solution Overview

Problem

Conventional hearing aids suffer from significant wind noise interference, leading users to disable their devices in windy conditions, as existing solutions are either too bulky or result in increased acoustic attenuation.

Innovation Solution

A hearing aid design featuring a wind shield with a sound transmission channel that guides sound to the microphone inlet, where airflow is converted from turbulent to laminar, optimizing wind noise suppression while minimizing acoustic attenuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If mechanical constructional measures are used to suppress wind noise, then wind noise suppression is improved, but the device becomes too big or bulky for hearing aid implementation

Engineering Contradiction:
Improvewind noise suppressionVSAvoiddevice size
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The patent employs a wind shield comprising a thin membrane that acts as a flexible barrier to reduce wind noise. This thin film approach provides effective wind noise suppression while maintaining a compact form factor suitable for hearing aids, avoiding the bulkiness of traditional mechanical solutions.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent optimizes the dimensions of the sound transmission channel, specifically setting the cross-sectional opening dimension between 0.15 mm and 0.5 mm. This parameter optimization allows the channel to maintain laminar flow characteristics that suppress wind noise while keeping the overall device size minimal for hearing aid application.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the sound transmission channel cross-section is reduced to suppress wind noise, then wind noise suppression is improved, but acoustic attenuation of desired sound increases

Engineering Contradiction:
Improvewind noise suppressionVSAvoidacoustic attenuation
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent carefully optimizes the sound transmission channel dimensions, specifically the cross-sectional opening between 0.15 mm and 0.5 mm, and the channel length between 1 mm and 3 mm. These parameter adjustments create a configuration that promotes laminar flow to suppress wind noise while minimizing acoustic attenuation of desired sounds through the channel.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a sound transmission channel with specific dimensional parameters that provide just enough flow restriction to suppress wind noise through laminar flow characteristics, without excessive restriction that would cause significant acoustic attenuation. The channel dimensions are optimized to achieve the minimum necessary suppression while preserving acoustic transmission.

Inventive Principle:
Principle #16Partial or excessive action

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 effectively reduces wind noise across a wide frequency band without compromising hearing aid sensitivity, allowing users to maintain device functionality in windy environments.

Implementation Method 1

wherein the air flow in the sound transmission channel is made laminar before reaching the microphone inlet

Methodology Applied
Scientific EffectTurbulent flow to laminar flow transition: Laminar Flow

Data Source

PatentEP2628313B1Hearing aid adapted for suppression of wind noise
Publication Date: 2014.11.26 WIDEX AS
  • EP2628313B1 patent drawingFigure 1
  • EP2628313B1 patent drawingFigure 2~3
  • EP2628313B1 patent drawingFigure 4

AI summary

A hearing aid (100) having a microphone, a signal processing unit, an electrical- acoustical output transducer, a housing (101) and a wind shield cover (102) wherein the housing has a surface with a microphone inlet (112, 113), and the wind shield cover is adapted to be attached to the housing, to cover the microphone inlet, to provide for sound to be guided in a gap between the wind shield cover and the housing, hereby providing for the transmission of sound from the surroundings and to said microphone inlet, wherein a first dimension of a cross-section of the gap is in the range between 0.15 mm and 0.5 mm, and wherein the minimum distance, along the gap, from the microphone inlet and to the opening of the gap, towards the surroundings, is at least 1 mm.