Bone-Conduction Speaker Sound Guiding Holes for Leakage Reduction

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Solution Overview

Problem

Bone conduction speakers experience sound leakage due to vibrations causing both the vibration board and housing to vibrate, generating air-borne sound that compromises privacy and disturbs others, and existing solutions like dual magnetic structures increase volume, weight, and cost while providing inadequate sealing.

Innovation Solution

Incorporating sound guiding holes in the housing to guide sound waves inside the speaker to interfere with leaked sound waves, reducing their amplitude through sound interference principles, without increasing volume or weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a dual magnetic structure and double-frame are used to reduce sound leakage, then sound leakage is reduced to some extent, but the volume, weight, and cost increase

Engineering Contradiction:

Improvesound leakageVSAvoidspeaker volume

Core Design Contradiction:

Object-generated harmful factorsVSVolume of moving object

Solution Approach 1:

The patent extracts the sound wave guidance function from the housing structure by incorporating sound guiding holes, separating the sealing function from the structural framework. This allows reducing sound leakage without requiring an additional outer frame, thus avoiding volume and weight increase.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses sound guiding holes (thin film structure) in the housing to guide sound waves, replacing the need for a bulky dual-frame structure. The holes provide acoustic control while maintaining the original housing dimensions and weight.

Inventive Principle:

Principle #30Flexible shells and thin films

2Object-generated harmful factors

If a dual magnetic structure and double-frame are used to reduce sound leakage, then sound leakage is reduced to some extent, but the cost increases

Engineering Contradiction:

Improvesound leakageVSAvoidmanufacturing cost

Core Design Contradiction:

Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The patent extracts the sound control function into simple sound guiding holes, eliminating the need for complex dual magnetic structures and additional frames. This simplification reduces manufacturing steps and material costs while maintaining sound leakage reduction effectiveness.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses simple sound guiding holes instead of expensive dual magnetic structures, opting for a cost-effective solution that achieves the desired acoustic control without requiring expensive materials or complex assembly processes.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If the housing is made to vibrate with the transducer, then sound transmission to bone is improved, but air-borne sound leakage increases

Engineering Contradiction:

Improvebone conduction effectivenessVSAvoidair-borne sound leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces sound guiding holes as an intermediary structure that mediates between the vibrating housing and the external environment. These holes guide sound waves in a controlled manner, allowing the housing to vibrate for effective bone conduction while controlling air-borne sound leakage through acoustic interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful air-borne sound leakage into a beneficial acoustic interference pattern. By strategically placing sound guiding holes, the leaked sound waves interfere with each other destructively, reducing overall sound leakage while maintaining the vibration-based bone conduction transmission.

Inventive Principle:

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

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

Effectively reduces sound leakage by up to 20 dB in specific frequency ranges, maintaining speaker performance and reducing noise disturbance without additional bulk or cost.

Implementation Method 1

the air inside the housing is pushed out of the housing through the at least one sound guiding hole, interferes with the leaked sound wave, and reduces an amplitude of the leaked sound wave

Methodology Applied

Scientific EffectSound interference: Interference

Data Source

PatentUS12407992B2Systems and methods for suppressing sound leakage

Publication Date: 2025.09.02 SHENZHEN SHOKZ CO LTD

AI summary

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.