Bone-Conduction Speaker Sound Guiding Holes for Leakage Reduction

Solution Overview

Problem

Bone conduction speakers experience sound leakage due to vibrations of the housing, which generates 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, utilizing principles of sound interference to reduce the amplitude of leaked sound waves by interfering with them, without increasing the speaker's 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 generation function from the housing structure by introducing a dedicated sound guiding hole. Instead of relying on the entire housing to generate sound waves, only a specific localized opening performs this function, allowing targeted sound wave emission for interference while maintaining housing integrity elsewhere.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The sound guiding hole acts as an intermediary element between the internal sound field and external environment. It mediates the sound wave generation process by providing a controlled pathway for air movement, enabling the housing to function as a sound source without requiring the entire structure to participate in vibration.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 weight increases

Engineering Contradiction:

Improvesound leakageVSAvoidspeaker weight

Core Design Contradiction:

Object-generated harmful factorsVSWeight of moving object

Solution Approach 1:

The patent extracts the sound wave generation function from the housing structure by introducing a dedicated sound guiding hole. Instead of relying on the entire housing to generate sound waves, only a specific localized opening performs this function, allowing targeted sound wave emission for interference while maintaining housing integrity elsewhere.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The sound guiding hole acts as an intermediary element between the internal sound field and external environment. It mediates the sound wave generation process by providing a controlled pathway for air movement, enabling the housing to function as a sound source without requiring the entire structure to participate in vibration.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If sealing measures are strengthened to prevent sound leakage, then sound leakage is reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvesound leakageVSAvoidmanufacturing ease

Core Design Contradiction:

Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The patent converts the harmful effect of air pushing against the housing (which causes sound leakage) into a beneficial effect. By providing a sound guiding hole, the air that would otherwise cause unwanted vibrations is redirected to create controlled sound waves for active noise cancellation, turning the problem into part of the solution.

Inventive Principle:

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

Solution Approach 2:

The system implements feedback by using the sound waves generated through the sound guiding hole to actively counteract the leaked sound waves. The housing vibrations that cause sound leakage are detected and counterbalanced by oppositely phased sound waves emitted through the same hole, creating a self-correcting system.

Inventive Principle:

Principle #23Feedback

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 targeted frequency ranges, maintaining speaker performance and reducing noise disturbance without increasing size or cost.

Implementation Method 1

the guided sound wave interferes with the leaked sound wave, which reduces the amplitude of the leaked sound wave

Methodology Applied

Scientific EffectSound interference: Interference

Data Source

PatentUS12457457B2Systems and methods for suppressing sound leakage

Publication Date: 2025.10.28 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.