Bone-Conduction Speaker Sound Guiding Holes for Leakage Suppression
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Solution Overview
Problem
Bone conduction speakers experience sound leakage due to housing vibrations, which can compromise privacy and disturb 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, where they interfere with leaked sound waves, reducing their amplitude and minimizing sound leakage without increasing volume or weight.
Engineering Contradictions & Design Principles
Engineering 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
Solution Approach 1:
The patent extracts the harmful vibration source from the housing by introducing a damping layer that absorbs vibrational energy, preventing the housing from acting as a sound radiation surface. This eliminates the need for complex dual-frame structures while maintaining sound leakage reduction.
Solution Approach 2:
A damping layer is introduced as an intermediary between the transducer/vibration board and the housing. This damping layer absorbs vibrational energy and prevents direct transmission to the housing, thereby reducing sound leakage without requiring structural modifications to the housing itself.
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 weight increases
Solution Approach 1:
The patent uses a lightweight damping layer material that is inexpensive and effective at absorbing vibrations. This replaces heavy magnetic components and complex framing structures, significantly reducing overall weight while maintaining sound leakage reduction functionality.
Solution Approach 2:
The damping layer serves as a lightweight intermediary that absorbs vibrational energy without adding significant weight. Unlike dual magnetic structures that require heavy magnets and complex assemblies, the damping layer provides effective vibration isolation with minimal mass addition.
3Object-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 manufacturing cost increases
Solution Approach 1:
The patent segments the vibration control function from the housing structure by adding a separate damping layer. This allows the housing to be manufactured using standard processes while the damping layer is applied as a separate component, simplifying manufacturing compared to integrated dual-frame structures.
Solution Approach 2:
The damping layer is introduced as a separate intermediary component that can be manufactured independently and applied to the housing. This modular approach simplifies manufacturing compared to complex dual magnetic structures that require precise assembly of multiple heavy components.
4Stability of the object's composition
If the housing is made rigid to support the transducer, then structural stability is improved, but sound leakage increases
Solution Approach 1:
The damping layer is placed between the transducer assembly and the rigid housing, serving as a mediator that absorbs vibrations before they can be transmitted to the housing. This allows the housing to remain rigid for structural support while preventing it from becoming a sound radiation surface.
Solution Approach 2:
The patent converts the harmful vibration transmission to the housing into a beneficial vibration absorption function by introducing the damping layer. The rigid housing that would normally radiate sound is instead protected from vibration transmission, turning a potential harmful effect into a beneficial isolation function.
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 sound guiding holes effectively reduce sound leakage by an average of 10 dB across relevant frequency ranges, maintaining speaker performance and size, and are easy to implement.
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
Data Source
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.