Configurable Earphone Microphone Array for Noise Rejection
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Solution Overview
Problem
Existing earphone designs with single omnidirectional microphones limit speech transmission quality and accuracy of speech-recognition engines in noisy environments, particularly when used with automated voice assistants.
Innovation Solution
Incorporating a microphone array in the earphone wires or earphones to enhance speech transmission quality, with two or more omnidirectional or directional microphones arranged in a line, grid, or frame, to create a directional beampattern that maximizes sensitivity towards the user's mouth while minimizing noise, and allowing for configuration modes such as single-sided, two-sided, enhanced directivity, stereo recording, and conference modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single omnidirectional microphone is used in the earphone wire, then the device complexity is low and manufacturing is simple, but the speech transmission quality and speech recognition accuracy deteriorate in noisy environments
Solution Approach 1:
The single omnidirectional microphone is segmented into multiple individual microphones arranged in an array. Each microphone captures sound from a specific direction, and their signals are processed separately before being combined to achieve directional sensitivity and noise rejection, thereby improving speech recognition accuracy without requiring a completely new device architecture
Solution Approach 2:
Multiple microphone signals are merged through signal processing techniques (beamforming) to create a unified directional response. The individual microphone outputs are combined in a way that enhances speech from the user's mouth direction while suppressing noise from other directions, achieving improved speech transmission quality through constructive signal integration
2Object-affected harmful factors
If a single omnidirectional microphone is used, then the device structure is simple, but the ability to reject ambient noise and focus on user speech deteriorates
Solution Approach 1:
Each microphone in the array is positioned at a specific location with a defined spatial relationship to the user's mouth. The signal processing applies local adjustments to each microphone's output based on its position, enhancing speech from the expected direction while attenuating noise from other directions, thereby achieving noise rejection through spatially-selective processing
Solution Approach 2:
The system uses feedback from multiple microphone channels to dynamically adjust the beamforming weights and directional patterns. By continuously analyzing the signals from all microphones and adjusting the processing parameters, the system adapts to changing acoustic environments and maintains optimal noise rejection performance
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
Significantly improves speech-signal-to-noise ratio and accuracy of speech recognition, particularly in noisy conditions, by using a microphone array to focus on the user's voice and reduce ambient noise interference.
Implementation Method 1
at least one microphone array comprising a plurality of microphones used to generate outgoing audio signals
Data Source
AI summary
Accessories for a telephone include at least one earphone and at least one microphone array having multiple microphones used to generate outgoing audio signals for (i) processing by a signal processor and (ii) transmission by the telephone. In one embodiment, two earphones are connected by two corresponding wires, and two microphone arrays, respectively connected to the two wires, are mechanically and electronically configurable in a plurality of use modes to generate outgoing audio signals for processing by the signal processor. The use modes include one or more and possibly all of a single-sided mode, a two-sided mode, an enhanced directivity mode, a stereo recording mode, a multichannel recording mode, a conference mode, and a two-dimensional-array mode, where one of the use modes is automatically detected by the signal processor based on the audio signals generated by the two microphone arrays.