Hearing Device Microphone Conduit Resonators

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Solution Overview

Problem

Existing hearing devices with multiple microphones face challenges in matching frequency characteristics due to physical embedding and conduit lengths, limiting layout flexibility and allowing ultrasonic frequencies to reach the microphones.

Innovation Solution

Designing hearing devices with conduits of differing lengths where each conduit forms an acoustic resonator, ensuring equal resonance frequencies for matching frequency characteristics, and positioning sound inlets to maintain directional signal processing while dampening ultrasonic frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conduits of equal length are used to match frequency characteristics, then frequency matching is improved, but physical layout flexibility is reduced

Engineering Contradiction:

Improvefrequency characteristic matchingVSAvoidphysical layout flexibility

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by introducing acoustic dampers that modify the acoustic impedance and phase characteristics of the conduits. By adjusting the damper parameters (position, length, cross-sectional area), the system can compensate for differences in conduit lengths while maintaining matched frequency characteristics, thus resolving the contradiction between frequency matching and layout flexibility.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The acoustic damper acts as an intermediary element between the sound inlet and the microphone transducer. It mediates the acoustic signal by introducing controlled impedance matching and phase adjustment, allowing conduits of different lengths to produce matched frequency responses at the microphone input.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conduits of different lengths are used to allow layout flexibility, then physical layout flexibility is improved, but frequency characteristic matching deteriorates

Engineering Contradiction:

Improvephysical layout flexibilityVSAvoidfrequency characteristic matching

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent uses parameter changes by introducing acoustic dampers with specific impedance values and phase characteristics. These dampers are designed to compensate for the phase and impedance differences caused by varying conduit lengths, thereby maintaining frequency characteristic matching while allowing layout flexibility.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The acoustic dampers are strategically positioned at specific locations within the conduits where they provide the most effective impedance matching. By localizing the damping effect to specific regions, the system maintains overall frequency matching while allowing different conduit lengths in different parts of the housing.

Inventive Principle:

Principle #3Local quality

3Device complexity

If no ultrasonic damping is provided, then device complexity is reduced, but ultrasonic frequencies reach the microphone causing harmful effects

Engineering Contradiction:

Improvedevice complexityVSAvoidultrasonic frequency interference

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The acoustic damper structure serves multiple functions simultaneously: it provides impedance matching for frequency characteristic matching, compensates for conduit length differences, and acts as an ultrasonic filter. By making the damper multi-functional, the patent avoids adding separate ultrasonic damping components, thus reducing overall device complexity while effectively blocking ultrasonic frequencies from reaching the microphone.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The acoustic damper acts as an intermediary barrier between the external acoustic environment and the microphone transducer. It mediates the acoustic signal by blocking ultrasonic frequencies while allowing audible frequencies to pass through, thus protecting the microphone from ultrasonic interference without requiring separate filtering mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach allows for greater physical layout flexibility of microphone units without compromising frequency or directional characteristics, effectively dampening ultrasonic frequencies and maintaining improved directional hearing capabilities.

Implementation Method 1

each conduit forming an acoustic resonator, ensuring equal resonance frequencies

Methodology Applied

Scientific EffectAcoustic resonance: Resonance

Implementation Method 2

dampening ultrasonic frequencies

Methodology Applied

Scientific EffectAcoustic damping: Damping

Data Source

PatentUS9185498B2Hearing device with two or more microphones and two or more resonators having different lengths and the same resonant frequency

Publication Date: 2015.11.10 OTICON

AI summary

The invention regards a hearing device with two or more microphone units each having a conduit leading from a respective sound inlet in the hearing-device housing to a respective transducer, wherein the lengths of the conduits may differ without causing a difference in the frequency characteristics of the microphone units and wherein ultrasonic frequencies may be dampened, while at the same time providing higher freedom in the physical layout of the hearing device. This is achieved in that each conduit comprises a chamber and a pipe forming a resonator, and in that the frequencies of resonance (f1, f2) of the resonators are equal.