Earmold Microphone Receiver Positioning for Occlusion Cancellation
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Solution Overview
Problem
Existing solutions for occlusion cancellation in hearing devices are inadequate, particularly in reducing near-field effects and providing accurate measurement of in-situ canal sound pressure, especially at higher frequencies.
Innovation Solution
An earmold design with a first microphone opening and a receiver opening positioned at specific distances from the tip end, allowing for improved occlusion cancellation through a processing unit with an occlusion cancelling unit that modifies output signals based on input from the microphone, thereby reducing near-field effects and enhancing closed-loop transfer functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the microphone opening and receiver opening are positioned close together, then the device structure is simplified, but near-field effects increase and measurement precision deteriorates
Solution Approach 1:
The earmold is segmented into distinct functional zones: the microphone opening is positioned in the upper portion of the ear canal while the receiver opening is positioned in the lower portion near the tympanic membrane. This spatial segmentation allows the microphone to measure sound pressure without being affected by the near-field effects generated by the receiver, thereby improving measurement precision while maintaining a relatively simple overall structure.
2Productivity
If the receiver opening is positioned close to the tip end, then sound transmission efficiency is improved, but near-field effects increase and occlusion cancellation performance deteriorates
Solution Approach 1:
The microphone acts as an intermediary element positioned between the external environment and the receiver. By placing the microphone opening in the upper ear canal away from the receiver, it can accurately measure the sound pressure that would otherwise be distorted by near-field effects from the receiver, enabling reliable occlusion cancellation while the receiver maintains its efficient position near the tympanic membrane.
3Ease of manufacture
If a single opening is used for both microphone and receiver, then manufacturing is simplified, but measurement accuracy and occlusion cancellation performance deteriorate
Solution Approach 1:
Instead of using a single opening, the earmold is designed with separate microphone and receiver openings positioned at different locations in the ear canal. This segmentation allows each opening to perform its specific function optimally - the microphone opening for accurate sound pressure measurement and the receiver opening for efficient sound delivery - while the manufacturing process remains relatively simple through standard molding techniques.
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 earmold design achieves improved occlusion cancellation by reducing near-field effects and enabling more accurate measurement of in-situ canal sound pressure, particularly at higher frequencies, resulting in enhanced sound transmission and pressure control.
Implementation Method 1
a first microphone connected to a first microphone opening for receiving sound in the ear canal
Implementation Method 2
a receiver opening for producing sound in the ear canal
Implementation Method 3
the processing unit comprises an occlusion cancelling unit configured to modify an output signal to the receiver based on an input signal from the first microphone
Data Source
AI summary
An earmold for an ear canal of a user, the earmold having an earmold shell and extending along an axis, the earmold shell having a tip end, the tip end facing a tympanic membrane of the user when worn by the user, the earmold includes: a first microphone connected to a first microphone opening for receiving sound in the ear canal, wherein the first microphone opening is arranged in a first position at a first distance from the tip end of the earmold shell; and a receiver opening for providing sound in the ear canal, wherein the receiver opening is arranged in a second position at a second distance from the tip end of the earmold shell; wherein the first position is different from the second position.