Microphone Array Guide Tubes for Acoustic Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microphone arrays in electronic devices face challenges due to acoustic isolating housings and limited spacing on printed circuit boards, which restrict directivity and sound reception.
Innovation Solution
The use of guide tubes extending from the housing to microphones, allowing external sound reception while maintaining acoustic isolation between chambers, and potentially incorporating acoustic dampers to equalize sound propagation delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If microphones are placed in a housing with acoustic isolators, then acoustic isolation is improved, but sound reception capability deteriorates
Solution Approach 1:
The housing is segmented into multiple acoustic chambers, each containing individual microphones. Acoustic isolators divide the internal space to prevent sound leakage between chambers, while guide tubes provide dedicated sound pathways from external holes to each microphone, maintaining isolation while enabling sound reception.
Solution Approach 2:
Guide tubes serve as intermediary elements that transmit sound from the external environment through the acoustic isolators to the microphones. These tubes act as controlled pathways that allow sound transmission while maintaining the acoustic isolation barrier between chambers.
2Volume of moving object
If microphones are mounted on a PCB with limited space, then device compactness is improved, but microphone spacing and directivity deteriorate
Solution Approach 1:
The microphone array configuration extends beyond the two-dimensional PCB surface into the three-dimensional space by using guide tubes that protrude from the housing. This allows microphones to be positioned at optimal spacing for directivity while keeping the PCB footprint compact, utilizing the vertical dimension and external space for array geometry.
3Adaptability or versatility
If guide tubes of different lengths are used, then flexible positioning is improved, but sound propagation delay equality deteriorates
Solution Approach 1:
Acoustic dampers are selectively placed in specific guide tubes based on their length and sound propagation characteristics. This local adjustment compensates for path length differences, ensuring that sound arrives at each microphone simultaneously despite variations in guide tube dimensions, thereby maintaining timing synchronization.
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 configuration enhances the directivity and sound reception capabilities of microphone arrays within electronic devices, offering flexible design options and improved audio signal quality.
Implementation Method 1
the plurality of guide tubes extend from the housing toward the plurality of microphones, whereby the plurality of microphones in the housing are capable of receiving external sound via the guide tubes
Implementation Method 2
the plurality of guide tubes includes a first guide tube and a second guide tube shorter than the first guide tube, and the acoustic damper is disposed in the second guide tube
Data Source
AI summary
An electronic device includes a housing, a plurality of microphones, and a plurality of guide tubes. The plurality of microphones are disposed in the housing. The plurality of guide tubes extend from the housing toward the plurality of microphones, whereby the plurality of microphones in the housing are capable of receiving external sound via the guide tubes.