Hearing Aid Active Occlusion Control Fitting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hearing aid devices with active occlusion control face challenges in achieving a balance between reducing occlusion effects and minimizing side effects like instability and unwanted sound amplification, requiring a method for precise and efficient fitting that adapts to individual needs.

Innovation Solution

A method using a complex frequency-dependent plant transfer function and objective frequency-dependent occlusion effect function to determine a compensator filter dataset, allowing for precise and efficient adaptation of active occlusion control, with predefining compensator filter candidates and user involvement in the fitting process to optimize results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a large vent is provided for passive occlusion control, then the occlusion effect is reduced, but feedback occurs and low-frequency sound delivery is compromised

Engineering Contradiction:
Improveocclusion effectVSAvoidfeedback control
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent replaces the mechanical/passive vent-based occlusion control system with an active electronic control system using a compensator filter. Instead of physically opening the ear canal with a large vent, the system uses signal processing to generate an anti-phase signal that actively cancels the occlusion effect, thereby avoiding feedback issues while maintaining occlusion reduction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from physical vent size to electronic filter characteristics. By adjusting the compensator filter parameters (frequency response, gain, phase), the system can dynamically control the occlusion effect without the mechanical constraints of vent size, enabling effective occlusion control without feedback.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If active occlusion control is implemented, then occlusion effect is reduced, but system instability occurs

Engineering Contradiction:
Improveocclusion effectVSAvoidcontrol loop stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback-based active occlusion control system where the compensator filter continuously monitors and adjusts the anti-phase signal based on the measured occlusion effect. This closed-loop feedback mechanism enables stable control by automatically adapting to changing conditions while maintaining system stability through controlled feedback gain.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If active occlusion control is implemented, then occlusion effect is reduced, but unwanted sound amplification occurs

Engineering Contradiction:
Improveocclusion effectVSAvoidunwanted sound amplification
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by designing the compensator filter to target specific frequency ranges where the occlusion effect occurs. Instead of uniformly amplifying all frequencies, the filter provides frequency-selective compensation, reducing occlusion at affected frequencies while maintaining or minimizing amplification of other frequency ranges where it is not needed.

Inventive Principle:
Principle #3Local quality

4Ease of manufacture

If traditional fitting methods are used, then fitting process is simple, but fitting precision and user-specific adaptation are insufficient

Engineering Contradiction:
Improvefitting process simplicityVSAvoidfitting accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent enables self-service fitting by implementing an automated fitting process where the hearing aid device itself performs measurements and automatically configures the compensator filter parameters. The device measures the user's specific occlusion characteristics and autonomously determines optimal filter settings, eliminating the need for complex manual fitting procedures while achieving high precision.

Inventive Principle:
Principle #25Self-service

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 method enables a precise and efficient fitting of hearing aids, providing a natural perception of the user's voice while maximizing occlusion control strength within system stability bounds, improving user acceptance and fitting accuracy.

Implementation Method 1

Active occlusion control is a method for reducing the occlusion effect actively. Actively means by destructive interference, i.e. emitting a kind of anti-sound.

Methodology Applied
Scientific EffectDestructive interference: Interference

Data Source

PatentEP2640095B2Method for fitting a hearing aid device with active occlusion control to a user
Publication Date: 2020.11.18 SONOVA AG
  • EP2640095B2 patent drawingFigure 1~2
  • EP2640095B2 patent drawingFigure 3
  • EP2640095B2 patent drawingFigure 4

AI summary

A hearing aid device (3) with an active occlusion control feature is fitted to a particular user. An occlusion control compensator filter (9) is configured with a dataset C. For finding an optimal dataset C various data is used, in particular data regarding a complex, frequency-dependent plant transfer function P from an input of a receiver (7) to an output of a canal microphone (8), data regarding an occlusion effect OE, data regarding a vent effect VE and/or data regarding a fundamental frequency F0 of the voice of the user. The optimal dataset C may be determined by a selection from a plurality of predefined raw datasets, such as C1, C2 and C3, and by a subsequent scaling with a scaling factor, such as g1, g2 and g3. Configurations with different datasets, such as CA * gA and CB * gB, may be presented to the user for a subjective evaluation.