Headset Gain Adjustment Using Ambient Noise Feedback
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Solution Overview
Problem
Bluetooth-enabled headsets face challenges in maintaining clear voice communications in environments with varying ambient noise levels, where users struggle to adjust volume settings to balance speech intelligibility and comfort, especially with wind noise interference.
Innovation Solution
A Bluetooth-enabled headset with a single microphone having two acoustic ports and dynamic noise compensation circuitry that adjusts gain based on signal-to-noise ratio, using a user-selectable gain and a target gain adjustment to optimize audio output, while a porous membrane reduces wind noise and the microphone's design enhances sensitivity to voice signals over ambient noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gain adjustment is increased to improve speech intelligibility in noisy environments, then speech clarity is improved, but comfort deteriorates in low noise conditions
Solution Approach 1:
The patent implements dynamic gain adjustment that automatically adapts to changing ambient noise levels. The system continuously monitors the acoustic environment and adjusts the gain parameter in real-time, transitioning from static to dynamic control. This resolves the contradiction by providing high gain only when noise is detected, and reducing gain in quiet conditions to maintain comfort.
Solution Approach 2:
The system employs feedback mechanisms by monitoring ambient noise levels and using this information to adjust the gain setting. The noise level detection circuit continuously provides feedback about the acoustic environment, which is then used to modify the speech signal amplification. This closed-loop control ensures speech intelligibility is maintained in noisy conditions while preventing excessive amplification in quiet environments.
2Object-affected harmful factors
If multiple microphones are used to improve noise rejection, then noise rejection capability is improved, but device complexity increases
Solution Approach 1:
The patent introduces a porous membrane as an intermediary element between the microphone and the ambient environment. This membrane selectively filters acoustic waves based on their characteristics - allowing speech frequencies to pass while attenuating wind noise and other unwanted sounds. This single-element intermediary provides noise rejection functionality without requiring multiple microphones or complex arrays.
Solution Approach 2:
The system utilizes a porous membrane with specific acoustic properties to achieve noise rejection. The porous structure allows certain frequencies to pass through while blocking others, creating a frequency-selective filter. This material-based approach provides effective noise rejection using a single microphone, avoiding the complexity of multi-microphone systems.
3Object-affected harmful factors
If wind noise reduction is implemented using porous membrane, then wind noise is reduced, but sensitivity to voice signals may deteriorate
Solution Approach 1:
The porous membrane is designed with spatially varying properties - the pore size, density, and distribution are optimized for different regions of the membrane. This local quality variation allows the membrane to selectively attenuate wind noise frequencies while maintaining high transmission for speech frequencies. The gradient structure ensures that different parts of the membrane perform different functions, preserving voice sensitivity while reducing wind noise.
Solution Approach 2:
The system optimizes the physical parameters of the porous membrane, including pore diameter, porosity ratio, and thickness, to achieve the desired frequency response. By carefully controlling these parameters, the membrane is designed to have high acoustic impedance for wind noise frequencies (low passage) and low impedance for speech frequencies (high passage). This parameter optimization ensures wind noise reduction without sacrificing voice signal sensitivity.
Data Source
AI summary
Methods and apparatuses for deriving a signal-to-noise ratio based at least in part on a measured level of a signal carrying far-end speech, and a measured level of a signal carrying ambient acoustic noise; determining a target gain adjustment based at least in part on the derived signal-to-noise ratio; applying the target gain adjustment to the signal carrying far-end speech to produce a gain-adjusted signal; and providing the gain-adjusted signal for audio output from a communications device.