Hearing Aid Counter Coil for Magnetic Noise Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hearing aids with telecoils face interference from ambient magnetic noises, which degrade sound quality and increase feedback, as they are sensitive to environmental magnetic fields.
Innovation Solution
Incorporating a counter coil that generates a counter magnetic field opposite to ambient noise, allowing for automatic adjustment of the hearing aid circuit to achieve an interference null, thereby maximizing the signal-to-noise ratio and reducing electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a telecoil is used to sense magnetic signals for hearing assistance, then the hearing aid can receive sound signals from magnetic sources (e.g., telephones, assistive listening systems), but the telecoil becomes sensitive to ambient magnetic noises, degrading sound quality and increasing feedback
Solution Approach 1:
The patent introduces a countercoil as an intermediary element that generates a counter magnetic field to cancel the ambient magnetic noise. This mediator (countercoil) does not directly process the sound signal but eliminates the harmful interference, allowing the telecoil to function effectively in noisy magnetic environments
2Object-affected harmful factors
If shielding materials are used to block ambient magnetic noise, then electromagnetic interference is reduced, but the device complexity and size increase due to additional shielding components
Solution Approach 1:
The patent replaces the mechanical/physical shielding approach with an electromagnetic field-based solution. Instead of using physical shielding materials to block magnetic noise, the invention uses a countercoil to generate an opposing magnetic field that actively cancels the interference, thereby eliminating the need for bulky shielding materials
Solution Approach 2:
The invention converts the harmful ambient magnetic noise into a beneficial effect by using the countercoil to generate an equal and opposite magnetic field. The harmful interference is transformed into a canceling force, achieving noise reduction through active electromagnetic compensation rather than passive shielding
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 counter coil effectively cancels ambient magnetic noise, achieving up to 30 dB attenuation of electromagnetic interference and reducing feedback, improving sound quality and eliminating the need for shielding materials.
Implementation Method 1
A telecoil, also referred to as a T-coil, T-switch, or a telephone switch, is such a magnetic sensor in a hearing aid that senses a magnetic signal representing a sound
Implementation Method 2
Incorporating a counter coil that generates a counter magnetic field opposite to ambient noise
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A hearing aid includes a magnetic sensor to sense a sound signal being a magnetic field. The magnetic sensor includes a telecoil to sensor the sound signal and a counter coil to cancel a noise signal resulting from electromagnetic interference. In one embodiment, a driver circuit for the counter coil allows for automatic adjustment of the hearing aid circuit for an interference null.