Microphone Gain Switching for Wider Dynamic Range
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Solution Overview
Problem
Conventional microphones with constant gain configurations fail to perform well in various scenarios, leading to overall performance degradation.
Innovation Solution
A microphone with an amplifier configured to have multiple gain levels, including unity and non-unity gains, utilizing a non-inverting amplifier and an analog switch, along with an Analog to Digital converter and bit shifter to adjust the digital audio signal based on selected gain levels, ensuring flexibility and maintaining dynamic range without altering sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a constant gain configuration is used in the microphone, then the structure is simple and easy to manufacture, but the performance degrades in scenarios different from the designed condition
Solution Approach 1:
The patent applies dynamics by making the gain configuration adjustable rather than fixed. The amplifier circuit includes multiple gain levels (e.g., 0 dB, 18 dB, 30 dB, 42 dB) that can be dynamically selected based on the acoustic environment. This allows the microphone to adapt its sensitivity to different scenarios such as far-field speech, near-field speech, or noisy environments, resolving the contradiction between structural simplicity and adaptability.
Solution Approach 2:
The patent changes the gain parameter of the amplifier circuit to achieve different performance characteristics. By providing multiple discrete gain levels and allowing dynamic selection among them, the system can optimize performance for different operating conditions without fundamentally changing the microphone structure, thus maintaining ease of manufacture while improving adaptability.
2Adaptability or versatility
If multiple gain levels are added to the amplifier, then the adaptability improves for different scenarios, but the device complexity increases
Solution Approach 1:
The patent segments the gain control into discrete, pre-defined levels (e.g., 0 dB, 18 dB, 30 dB, 42 dB) rather than continuous adjustment. Each gain level corresponds to specific resistor configurations in the feedback network. This segmentation simplifies the control logic and makes the system more manageable while still providing adequate adaptability for different scenarios.
Solution Approach 2:
The amplifier circuit is designed to perform multiple functions through a single multi-functional gain control mechanism. The same amplifier circuit can operate at different gain levels depending on the selected configuration, eliminating the need for separate amplifier circuits for different scenarios. This multi-functionality reduces overall device complexity while maintaining adaptability.
3Measurement precision
If the gain is increased to capture distant sounds, then the sensitivity for far-field audio improves, but the dynamic range may be compromised
Solution Approach 1:
The patent uses dynamic gain selection to maintain optimal performance across different listening conditions. When capturing far-field audio, a higher gain level (e.g., 30 dB or 42 dB) is selected to improve sensitivity. When capturing near-field audio or in noisy environments, a lower gain level (e.g., 0 dB or 18 dB) is selected to preserve dynamic range. This dynamic adjustment resolves the contradiction between sensitivity and dynamic range consistency.
Solution Approach 2:
The patent changes the gain parameter based on the acoustic scenario to optimize both sensitivity and dynamic range. By providing multiple discrete gain levels, the system can select the appropriate parameter setting for each scenario, ensuring that far-field audio is captured with sufficient sensitivity while near-field audio maintains proper dynamic range without being over-amplified.
Data Source
AI summary
The present disclosure provides a microphone including a main body, where an audio signal is generated in the main body based on the sound level and some other properties received, and an amplifier disposed in the main body, where the amplifier is adapted to amplify the audio signal, with the amplifier able to be configured with multiple gain levels. The present disclosure further provides a method for processing audio signals including: acquiring an audio signal; selecting a gain from multiple gain levels of an amplifier based on a property of the acquired audio signal, where the amplifier is built in a main body of a microphone; and modifying the digital representation after analog to digital conversion of the acquired audio signal according to the selected gain.