Helmet Microphone Noise Reduction via Dual-Sensor Segmentation
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Solution Overview
Problem
Existing communication systems in protective helmets fail to effectively reduce ambient noise in voice microphone signals, leading to impaired communication quality for both the wearer and communication partners, especially in noisy environments.
Innovation Solution
A protective helmet with two microphones, one positioned inside the chin guard for speech capture and another on the outside or strategically placed on the chin guard to capture ambient noise, combined with an electronic circuit for noise reduction using adaptive filtering to generate a difference signal that reduces ambient noise in the speech signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single microphone is used inside the chin guard to capture speech, then the speech signal can be recorded, but the ambient noise significantly impairs communication quality
Solution Approach 1:
The patent divides the audio capture function into two separate microphones: one positioned inside the chin guard to capture speech signals and another positioned on the outside of the helmet to capture ambient noise. This segmentation allows independent optimization of each microphone's position and function, enabling the speech microphone to focus on voice capture while the noise microphone specifically targets environmental noise for subsequent cancellation processing.
Solution Approach 2:
The patent introduces a noise microphone as an intermediary element that captures ambient noise separately from the speech signal. This intermediary noise signal serves as a reference that can be processed through adaptive filtering to generate anti-noise signals, which are then combined with the speech signal to cancel out ambient noise interference, thereby improving overall communication quality.
2Object-affected harmful factors
If ambient noise microphones are positioned near the speakers inside the helmet, then active noise canceling can be implemented at the ear, but the speech signal recorded at the chin guard remains afflicted with loud ambient noise
Solution Approach 1:
The patent separates the noise cancellation function into two independent systems: one for ear-level noise cancellation using microphones near the speakers, and another for speech signal purification using a noise microphone positioned on the outside of the helmet. This segmentation allows each system to optimize its performance independently, with the speech-focused noise microphone capturing ambient noise that affects the chin guard microphone signal, enabling effective noise removal from the speech transmission path.
3Object-affected harmful factors
If multiple microphones are added to the helmet, then noise reduction capability is improved, but the device complexity increases
Solution Approach 1:
The patent extracts the noise sampling function from the existing helmet microphone system and implements it as a separate, dedicated noise microphone positioned on the outside of the helmet. This extraction allows the noise microphone to specifically capture ambient noise without being contaminated by speech signals, while the existing chin guard microphone continues to focus on speech capture. This functional separation simplifies the overall system architecture compared to using multiple microphones in complex configurations.
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 significantly improves communication clarity by effectively reducing ambient noise, enhancing the intelligibility of speech signals for both the wearer and communication partners, even in noisy environments.
Implementation Method 1
an electronic circuit for noise reduction using adaptive filtering to generate a difference signal that reduces ambient noise in the speech signal
Data Source
AI summary
Protection helmets may include integrated communication systems to allow the wearer to communicate with other persons. In a very loud environment, a reduction of ambient noise may be helpful, for example, for improving wireless communication. An improved protection helmet includes a helmet shell, a chin guard, a first microphone mounted on the inside of the chin guard and facing the mouth of the wearer, a second microphone mounted on the outside, the upper side or the lower side of the chin guard and not facing the mouth of the wearer, an electronic noise reduction unit generating a difference signal between signals of the first and the second microphone, and at least one interface for outputting the difference signal. Ambient noise in the signal of the first microphone can be reduced with the signal of the second microphone.