Non-axisymmetric Phase Plug for Ear Canal Audio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phase plugs in acoustic devices are symmetric and require horns to expand sound waves, which limits their application in environments where sound wave decomposition is not necessary, such as in ear canals, and fails to provide optimal audio quality.
Innovation Solution
The development of non-axisymmetric phase plugs that eliminate the need for horns by guiding sound waves through non-axisymmetric waveguides directly to the ear canal, ensuring phase coherence without expansion or decomposition, and are designed to fit various ear shapes with interchangeable components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional symmetric phase plugs with horns are used, then sound waves are properly expanded and directed, but the device cannot be effectively applied in ear canals and creates unnecessary complexity
Solution Approach 1:
The patent applies asymmetry by designing a non-axisymmetric phase plug that eliminates the traditional horn structure. The phase plug has an asymmetric geometry with a first surface facing the compression driver and a second surface facing the ear canal, allowing it to function without the symmetric horn expansion structure. This asymmetric design enables direct coupling to the ear canal while maintaining acoustic performance, resolving the contradiction between adaptability to ear canals and device complexity.
2Reliability
If horns are used to expand sound waves, then acoustic impedance matching is achieved, but the device size increases and cannot fit in ear canals
Solution Approach 1:
The patent applies the extraction principle by removing the horn component entirely from the phase plug design. The traditional horn structure used for acoustic impedance matching and sound wave expansion is extracted/eliminated, leaving only the essential non-axisymmetric phase plug body. This extraction achieves acoustic impedance matching through the phase plug's asymmetric geometry alone, significantly reducing device volume to enable ear canal fitting while maintaining reliability of acoustic performance.
3Ease of manufacture
If symmetric phase plug design is used, then manufacturing is simplified, but audio quality is not optimized for ear canal applications
Solution Approach 1:
The patent applies local quality by designing the phase plug with asymmetric geometry optimized for specific acoustic functions in ear canal applications. Different regions of the phase plug have different characteristics: the first surface is optimized for coupling with the compression driver, the second surface for coupling with the ear canal, and the internal structure for controlling sound wave propagation. This localized optimization of different regions achieves superior audio quality and acoustic performance precision, compensating for the increased manufacturing complexity of asymmetric shapes.
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 enhances audio quality by improving frequency response, reducing sound diffraction, and decreasing distortion while allowing for a secure fit in differently shaped ear canals, providing improved acoustic loading and reflection characteristics.
Implementation Method 1
The guide (120) extends from the compression member (2) to a phase plug tip (84), such that the guide (120) is non-axisymmetric to a central axis (93) of the compression member (2)
Data Source
AI summary
Phase plugs (70) and related audio devices (100, 105) and methods comprise various compression members (2), and guides (120) extending from the compression members (2) to tips (84), are configured such that central axes (93, 99) defined perpendicular to compression members (2) and/or diaphragms (94) are asymmetric and/or non-axisymmetric to the central axes (93, 99).