Hearing Aid Wind Shield Gap Design for Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hearing aids struggle with significant wind noise suppression, leading users to often switch them off in windy conditions due to noise levels reaching 100 dB Sound Pressure Level, which affects acoustic perception and is exacerbated by turbulent airflow.
Innovation Solution
A hearing aid design featuring a microphone inlet with a sound transmission channel that converts turbulent airflow into laminar flow before reaching the microphone, utilizing a gap between the housing and wind shield cover with specific dimensions (0.15 mm to 0.5 mm spacing and 2 mm to 3 mm minimum distance) to effectively suppress wind noise while minimizing acoustic attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a wind shield cover is added to suppress wind noise, then wind noise suppression is improved, but acoustic attenuation of desired sound increases
Solution Approach 1:
The wind shield cover is designed with a specific gap structure (0.15-0.5mm spacing) that creates different flow characteristics for different types of sound waves. The gap dimensions are optimized to allow desired acoustic frequencies to pass through while creating turbulent flow conditions that suppress wind noise, thus achieving local quality differentiation in noise filtering.
Solution Approach 2:
The invention changes the physical parameters of the wind shield cover, specifically the gap spacing (0.15-0.5mm) and the distance from microphone inlet to edge (2-3mm). These parameter changes create a flow regime that suppresses wind noise while maintaining acoustic transmission, resolving the contradiction between noise suppression and sound attenuation.
2Object-affected harmful factors
If mechanical constructional measures are used to counteract wind noise, then wind noise suppression is improved, but device size increases
Solution Approach 1:
The wind shield cover is implemented as a thin shell structure with a gap, rather than a bulky mechanical barrier. This thin-film approach provides wind noise suppression functionality while maintaining a compact form factor suitable for hearing aid integration, avoiding the volume increase associated with traditional mechanical measures.
3Object-affected harmful factors
If the gap spacing is reduced to suppress wind noise, then wind noise suppression is improved, but acoustic transmission is reduced
Solution Approach 1:
The gap spacing (0.15-0.5mm) is set to a partial dimension that is sufficient to suppress wind noise but not so small as to block acoustic transmission. This partial action approach achieves the minimum necessary suppression while maintaining adequate sound transmission, avoiding excessive gap reduction that would compromise acoustic reliability.
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 solution significantly improves wind noise suppression across a wide frequency band without compromising hearing aid sensitivity, allowing users to maintain acoustic perception in windy environments.
Implementation Method 1
a sound transmission channel adapted to provide for sound to be guided from the surroundings, through the interior of the housing and to the microphone inlet, wherein a first dimension of a cross-section of the sound transmission channel is in the range between 0.15 mm and 0.5 mm
Data Source
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.