Hearing Aid Microphone Inlet with Flexible Rubber Seal
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Solution Overview
Problem
Hearing instrument microphones face challenges in maintaining a tight seal to prevent contamination and effectively functioning as an acoustic low-pass filter, while avoiding the entry of contaminants like dirt, sweat, and earwax.
Innovation Solution
The design incorporates an inlet system with a main body portion having separate recesses for microphones, featuring sound channels and cavities that provide a directional microphone system, are made of vulcanized rubber for noise dampening, and allow for easy cleaning and replacement, with the option of a removable lid for access to cavities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tight seal is provided between the inlet member and hearing instrument casing, then contamination prevention is improved, but manufacturing precision requirements increase due to tolerance variations
Solution Approach 1:
The inlet member is made of vulcanized rubber, a flexible material that can deform to accommodate tolerance variations in the hearing instrument casing. This flexibility allows the inlet member to form a reliable seal across all tolerance cases without requiring extremely tight manufacturing tolerances, thus resolving the contradiction between seal tightness and manufacturing precision.
2Ease of operation
If the inlet opening is situated at the surface of the hearing instrument for easy sound entry, then ease of operation is improved, but contamination risk increases
Solution Approach 1:
The vulcanized rubber inlet member acts as a flexible barrier that allows sound to pass through while blocking contaminants. The material's properties enable it to maintain a seal that prevents dirt, sweat, and earwax from entering the microphone while still permitting acoustic energy to reach the microphone efficiently.
Solution Approach 2:
The inlet member can be designed with porous characteristics that allow sound waves to pass through while physically blocking larger contaminant particles. This selective permeability enables sound entry while preventing contaminant ingress, resolving the contradiction between ease of operation and contamination protection.
3Ease of manufacture
If a separate hard plastic inlet part is used with glue sealing, then ease of manufacture is improved, but reliability of seal decreases due to potential sealing failures
Solution Approach 1:
By using a vulcanized rubber inlet member instead of a hard plastic part requiring glue sealing, the invention eliminates the potential for sealing failures associated with adhesive bonds. The flexible rubber material can be directly fitted and sealed, providing more reliable and durable sealing while remaining easy to manufacture and install.
4Object-generated harmful factors
If the inlet member is made of vulcanized rubber for noise dampening, then object-generated harmful factors are reduced, but manufacturing complexity increases
Solution Approach 1:
The use of vulcanized rubber provides inherent noise dampening properties due to the material's viscoelastic characteristics. While the material selection adds some complexity, the vulcanization process is a well-established manufacturing technique that allows the inlet member to be molded into the required shape with integrated sealing features, balancing noise reduction benefits with manageable manufacturing complexity.
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
This solution effectively reduces the risk of contamination, provides an acoustic low-pass filter with adjustable frequency characteristics, and facilitates easy maintenance by allowing the removal and replacement of the inlet member, ensuring the microphone remains protected and functional.
Implementation Method 1
the inlet member is made of vulcanized rubber... made of vulcanized rubber for noise dampening
Implementation Method 2
sound channels and cavities that provide a directional microphone system... function as an acoustic low-pass filter
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
The disclosure relates to an inlet member for a microphone system in a hearing instrument, such as a hearing aid, wherein the inlet member has a main body portion having a first portion and a second portion, the second portion being provided with a first recess for accommodating a microphone comprising a snout for conducting sound energy into the interior of the microphone, wherein the first recess is provided with a sound channel (8) formed for engagement with the snout of the microphone, where the sound channel at the end hereof facing away from the microphone is acoustically coupled to a third recess in the first portion, the third recess being defined by wall portions that provide a seal to corresponding inner surface portions of a hearing instrument, in which the inlet member is mounted.