Microphone Gain Control Using ToF Range Sensing for Voice Detection
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Solution Overview
Problem
Existing voice recognition systems face challenges in setting the audio gain, leading to distortion from high gain settings amplifying ambient noise and failing to detect desired sounds at low gain settings, while laser range-finding systems experience interference due to overlapping emissions in multi-device environments.
Innovation Solution
A system that uses a range-finding laser to determine the distance to a sound source, adjusting the audio amplifier gain based on this distance, either linearly or logarithmically, to optimize sound detection and reduce interference by correlating the gain with the distance and sound absorption characteristics of surrounding surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gain is set high to detect desired sounds, then sensitivity improves, but distortion and ambient noise amplification worsen
Solution Approach 1:
The patent implements dynamic gain adjustment by continuously monitoring distance measurements from the laser range finder and automatically adjusting the audio gain accordingly. This replaces static gain settings with a dynamic system that adapts to changing spatial conditions, allowing the system to maintain optimal sensitivity without distortion by adjusting gain in real-time based on actual distance to sound sources.
Solution Approach 2:
The system changes the gain parameter based on distance measurements. By establishing a relationship between distance and optimal gain levels (through iterative detection or direct correlation), the system automatically adjusts the amplification parameter to match the spatial context, thereby improving detection sensitivity while preventing distortion and ambient noise amplification that would occur with fixed high gain settings.
2Object-generated harmful factors
If the gain is set low to reduce ambient noise, then noise amplification decreases, but desired sound detection capability worsens
Solution Approach 1:
The system dynamically adjusts gain based on real-time distance measurements rather than using a fixed low gain setting. This allows the system to maintain low gain when ambient noise is a concern while automatically increasing gain when distance measurements indicate that desired sounds need enhanced detection, thus resolving the contradiction between noise reduction and detection capability.
Solution Approach 2:
The patent implements a feedback mechanism where the laser range finder continuously provides distance information to the audio processing system, which then adjusts gain accordingly. This closed-loop feedback system ensures that gain is optimized based on actual spatial conditions, preventing both excessive ambient noise amplification and insufficient desired sound detection that would occur with fixed gain settings.
3Productivity
If multiple devices use laser range finders simultaneously, then comprehensive environmental mapping improves, but mutual interference from overlapping emissions worsens
Solution Approach 1:
The patent employs periodic or time-division multiplexed laser emissions where multiple devices take turns emitting laser beams in different time slots. This periodic action allows comprehensive environmental mapping to be achieved by multiple devices while preventing mutual interference, as each device emits only during its assigned time period rather than continuously overlapping with others.
Solution Approach 2:
The system segments the environmental mapping task across multiple devices operating in coordinated time slots. Each device is assigned specific time periods to emit laser beams and perform ranging, dividing the overall mapping productivity among multiple devices without causing interference. This segmentation of temporal resources allows comprehensive coverage while eliminating the harmful overlapping emissions effect.
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 approach improves voice recognition by dynamically adjusting the gain based on distance and sound absorption, enhancing signal-to-noise ratio and reducing interference in multi-device environments, thereby improving the accuracy and effectiveness of voice recognition and laser range-finding systems.
Implementation Method 1
laser range-finding systems that use time of flight (ToF) principles to find distances from an origin to various objects
Implementation Method 2
receive at least a first acoustic signal from a source of sound, and to determine at least an azimuthal direction to the source of sound from an origin based at least in part on the first acoustic signal
Data Source
AI summary
Range to a human speaker is determined using a laser-based time of flight (ToF) system, with the range then being used to adjust the gain of a microphone receiving the speaker's voice. If desired, an acoustic-based Direction of Arrival (DoA) system uses acoustic information to determine the direction of incoming sound, such as a person talking, and the direction of the sound is then used to focus the area of laser illumination.