Bone Conduction Module Structure for Acoustic Leakage Suppression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional headsets suffer from insufficient countermeasures against acoustic sound leakage, particularly when used at high volumes in public places.

Innovation Solution

A bone conduction acoustic module with a piezoelectric element, a bone conduction member, and a support member that includes vacant portions on both sides of the piezoelectric element to suppress sound leakage by canceling out vibrations through opposite phases, and is mounted on a frame to transmit vibrations to the mastoid projection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional headsets are used at high volumes, then audio output is improved, but acoustic sound leakage increases

Engineering Contradiction:
Improveaudio outputVSAvoidacoustic sound leakage
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful vibrations generated by the piezoelectric element into beneficial opposite-phase vibrations that cancel sound leakage. The support member structure allows vibrations to propagate to the housing and then to the outer surface, where they interfere destructively with the original sound waves, transforming the harmful vibration energy into a beneficial sound cancellation mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent utilizes mechanical vibrations generated by the piezoelectric element and transmitted through the support member and housing to create opposite-phase vibrations on the outer surface. These vibrations mechanically interfere with sound waves to suppress acoustic sound leakage, directly applying vibration principles to solve the sound leakage problem.

Inventive Principle:
Principle #18Mechanical vibration

2Stability of the object's composition

If the support member is solid on all sides of the piezoelectric element, then structural stability is improved, but acoustic sound leakage increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidacoustic sound leakage
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The support member is designed with non-uniform density distribution, having different densities at different locations. The first density region and second density region create varying vibration transmission characteristics, allowing the structure to maintain stability where needed while suppressing sound leakage through strategic density variations that control vibration propagation paths.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the density parameter of the support member by introducing multiple density regions with different density values. This parameter change allows the support member to selectively transmit or block vibrations at different locations, maintaining structural stability while suppressing acoustic sound leakage through controlled density variations.

Inventive Principle:
Principle #35Parameter changes

3Force

If the piezoelectric element is tightly coupled with the housing, then vibration transmission is improved, but acoustic sound leakage increases

Engineering Contradiction:
Improvevibration transmissionVSAvoidacoustic sound leakage
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The support member acts as an intermediary between the piezoelectric element and the housing, mediating the vibration transmission. It selectively transmits vibrations to the housing while blocking direct acoustic coupling, serving as a vibration filter that maintains mechanical force transmission while preventing sound leakage through its density-controlled structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support member is segmented into different density regions (first density region and second density region) with different vibration transmission characteristics. This segmentation allows different portions of the support member to perform different functions: transmitting vibrations where needed while blocking sound leakage paths, thereby resolving the contradiction between vibration transmission and sound leakage.

Inventive Principle:
Principle #1Segmentation

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 module effectively suppresses acoustic sound leakage by reducing vibration transmission to the housing and enhancing bone conduction, maintaining sound quality and reducing noise leakage.

Implementation Method 1

a piezoelectric element configured to generate vibrations

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a bone conduction member configured to abut the piezoelectric element and transmit vibrations of the piezoelectric element to a bone

Methodology Applied
Scientific EffectMechanical vibration transmission: Vibration

Implementation Method 3

the support member includes a first vacant portion where the support member is vacant on a first flat surface side and a second vacant portion where the support member is vacant on a second flat surface side... acoustic sound leakage can be suppressed

Methodology Applied
Scientific EffectVibration cancellation: Damping

Data Source

PatentEP4645897A1Bone conduction acoustic module and acoustic system
Publication Date: 2025.11.05 TDK CORP
  • EP4645897A1 patent drawingFigure 1~2
  • EP4645897A1 patent drawingFigure 3~4
  • EP4645897A1 patent drawingFigure 5~6

AI summary

A bone conduction acoustic module includes a piezoelectric element, a bone conduction member configured to abut the piezoelectric element and transmit vibrations of the piezoelectric element to a bone, and a support member configured to directly or indirectly support the piezoelectric element and the bone conduction member. The piezoelectric element includes a first flat surface abutting the bone conduction member and a second flat surface located on an opposite side of the first flat surface. The support member includes a first vacant portion where the support member is vacant on a first flat surface side and a second vacant portion where the support member is vacant on a second flat surface side.