Balanced Armature Receiver with External Back Volume
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As sound-producing acoustic devices like balanced armature receivers are miniaturized, they experience increased acoustic stiffness, leading to reduced sound output without a corresponding reduction in size, necessitating a solution to enhance sound output while maintaining or reducing size.
Innovation Solution
The implementation of a balanced armature acoustic receiver with multiple internal volumes and a back-volume increasing structure that acoustically couples additional volume to the back volumes, increasing acoustic compliance without increasing the overall size, achieved through a housing design with separate front and back volumes and an acoustic seal to accommodate mechanical coupling while providing additional volume externally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of balanced armature receivers is reduced to accommodate smaller space allocations, then the device can be integrated into increasingly smaller hearing devices, but the acoustic stiffness increases and sound output is reduced
Solution Approach 1:
The patent introduces a back volume chamber that extends in the longitudinal dimension of the receiver, effectively increasing the acoustic compliance volume without increasing the cross-sectional area. This allows the receiver to maintain a compact form factor while achieving the necessary acoustic volume for reduced stiffness.
Solution Approach 2:
The back volume chamber is nested within the receiver housing structure, with the armature assembly positioned within this chamber. The diaphragm is coupled to the armature and forms part of the chamber structure, creating a nested arrangement that maximizes volume utilization within the constrained space.
2Volume of moving object
If the size of balanced armature receivers is reduced, then the device can be miniaturized, but the acoustic compliance decreases and sound output is reduced
Solution Approach 1:
The back volume chamber extends the acoustic compliance volume in the longitudinal direction, allowing the receiver to achieve sufficient acoustic volume for adequate sound output while maintaining a compact cross-sectional footprint suitable for miniaturized hearing devices.
Solution Approach 2:
The patent modifies the acoustic compliance parameter by introducing the back volume chamber, which increases the effective volume available for acoustic compliance without proportionally increasing the overall receiver size, thereby maintaining sound output performance.
3Object-generated harmful factors
If the acoustic compliance is increased to reduce acoustic stiffness, then the sound output is enhanced, but the overall size of the device increases
Solution Approach 1:
The back volume chamber is configured to extend in the longitudinal dimension rather than increasing the cross-sectional area, allowing the receiver to achieve increased acoustic compliance volume while maintaining a compact overall form factor suitable for modern hearing devices.
Solution Approach 2:
The diaphragm is implemented as a thin, flexible membrane that couples the armature to the back volume chamber, allowing efficient transmission of acoustic energy while occupying minimal space and contributing to the overall compact design.
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
This design effectively reduces acoustic stiffness, allowing the armature and diaphragms to move more freely, thereby enhancing the acoustic output of the receiver by increasing total acoustic compliance by up to several hundred percent, thus improving sound production without enlarging the device.
Implementation Method 1
The coil is disposed about a portion of an armature (also known as a reed), a movable portion of which is disposed in equipoise between magnets, which are typically retained by a yoke. Application of the excitation or input signal to the receiver coil modulates the magnetic field, causing deflection of the reed between the magnets.
Implementation Method 2
an acoustic seal acoustically separates one of the front volumes from one of the back volumes while accommodating the mechanical coupling of the armature to one of the diaphragms
Implementation Method 3
a back-volume increasing structure that acoustically couples additional volume to the back volumes, increasing acoustic compliance without increasing the overall size
Data Source
AI summary
A sound-producing balanced armature receiver, as disclosed, includes a receiver housing with a first internal volume, a second internal volume, and a sound outlet. The receiver includes a first diaphragm separating the first internal volume into a first front volume and a first back volume and a second diaphragm separating the second internal volume into a second front volume and a second back volume. The receiver also includes a motor inside the first back volume of the housing such that the motor includes an armature mechanically coupled to both the first diaphragm and the second diaphragm, an acoustic seal between the first front volume and the second back volume such that the acoustic seal accommodates the mechanical coupling of the armature to the second diaphragm while providing acoustic separation between the first internal volume and the second internal volume, and a back-volume increasing structure attached externally to the housing and acoustically coupled with the second back volume to provide additional volume to the second back volume.