Bone Conduction Speaker Sound Leakage Suppression via Guided Interference
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Solution Overview
Problem
Bone conduction speakers experience sound leakage due to vibrations causing air displacement, which can compromise privacy and disturb others, and existing solutions like dual magnetic structures are inefficient in reducing leakage while increasing weight and cost.
Innovation Solution
Incorporating sound guiding holes in the housing of the bone conduction speaker to guide sound waves inside the device outwards, where they interfere with leaked sound waves, reducing their amplitude and minimizing leakage without increasing the device's 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 and weight of the speaker increase
Solution Approach 1:
The patent extracts the harmful sound waves generated by housing vibration and guides them through dedicated sound guiding holes to a specific discharge location. By separating the leakage reduction function from the overall housing structure and using simple holes instead of complex dual-frame structures, the design reduces weight while effectively managing sound leakage.
Solution Approach 2:
The patent changes the parameters of sound wave management by creating specific sound guiding holes with controlled positions, sizes, and orientations. These holes guide sound waves along specific paths to achieve interference and cancellation effects, providing an alternative to the heavy dual magnetic structure while maintaining effectiveness.
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
Solution Approach 1:
The patent extracts the sound guidance function from complex magnetic structures and implements it through simple holes in the housing. This extraction of the essential function (guiding sound waves) from complex components (dual magnetic structure) significantly reduces manufacturing cost while maintaining the ability to reduce sound leakage.
Solution Approach 2:
The patent uses simple, inexpensive sound guiding holes instead of expensive dual magnetic structures. These holes can be easily manufactured through standard machining or molding processes, making the solution cost-effective and suitable for mass production.
3Reliability
If the housing is made to vibrate with the transducer, then bone conduction is achieved, but air is pushed and sound leakage occurs
Solution Approach 1:
The patent converts the harmful effect of housing vibration (which causes sound leakage) into a beneficial effect by guiding the resulting sound waves through sound guiding holes to create controlled interference patterns. The same vibration that causes leakage is now used to generate counteracting sound waves that reduce overall leakage.
Solution Approach 2:
The patent introduces sound guiding holes as intermediary structures that mediate between the housing vibration and the external environment. These holes guide sound waves in a controlled manner, allowing the housing to vibrate for bone conduction while managing the resulting air displacement to reduce sound leakage.
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 solution effectively reduces sound leakage by up to 20 dB in specific frequency ranges, maintaining the speaker's reliability and cost-effectiveness while improving user privacy and reducing environmental disturbance.
Implementation Method 1
The transducer 1220 may transduce electrical signals to mechanical vibrations
Implementation Method 2
The vibration board 1210 may stretch out from the opening of the housing 110 and contact with human skin to pass vibrations to auditory nerves through human tissues and bones
Implementation Method 3
a portion of the vibrating board 1210 and the housing 110 that are not in contact with human issues may nevertheless push air. Air sound may thus be generated by the air pushed by the portion of the vibrating board 1210 and the housing 110
Implementation Method 4
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.