Environmental Noise Compensation Using Listener-Position Noise Sensing
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Solution Overview
Problem
Existing noise compensation systems in audio devices face challenges in accurately determining the impact of ambient noise on listeners due to the proximity ambiguity problem, where sound pressure levels measured at one point are not representative of other points in a reverberant room, leading to incorrect volume adjustments.
Innovation Solution
The system measures ambient noise at a listener's position by inferring the noise source proximity and using critical distance analysis, along with frequency-dependent reverberation times and room volume, to calculate confidence scores for noise compensation, applying unconstrained or modified noise compensation based on these scores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sound pressure levels are measured at one point in a reverberant room, then the measurement is simple and quick, but the measurement is not representative of other points leading to incorrect noise compensation
Solution Approach 1:
The system performs preliminary measurements of reverberation time and critical distance before noise compensation. These pre-measured acoustic parameters are stored and used to guide subsequent noise measurements, ensuring that measurements are taken at appropriate distances from noise sources based on the room's acoustic characteristics.
Solution Approach 2:
The system introduces critical distance and reverberation time as intermediary parameters that mediate between the microphone measurement location and the listener position. These intermediaries allow the system to translate measurements taken at one location into accurate noise estimates at the listener's position by accounting for room acoustic effects.
2Measurement precision
If noise compensation is applied without considering critical distance, then the processing is faster and simpler, but the noise compensation is inaccurate for listeners at different positions
Solution Approach 1:
Critical distance and reverberation time are pre-measured and stored before noise compensation operations. This preliminary action eliminates the need for real-time calculation of these parameters during noise compensation, reducing computational time while maintaining accuracy.
Solution Approach 2:
The noise compensation system dynamically adjusts compensation levels based on the calculated distance between the noise source and listener, using the pre-measured critical distance as a reference. This dynamic adjustment ensures accurate compensation for listeners at different positions without requiring real-time recalculation of acoustic parameters.
3Measurement precision
If ambient noise is measured at the audio device location, then the measurement is easy to obtain, but it does not represent the noise level at the listener's position
Solution Approach 1:
The system uses critical distance and reverberation time as intermediary parameters to bridge the gap between the audio device location and listener position. By measuring ambient noise at the device and using these intermediaries to account for acoustic propagation effects, the system accurately estimates noise levels at the listener's position without requiring direct measurement there.
Solution Approach 2:
The system replaces the mechanical approach of placing a microphone at the listener's position with an acoustic modeling approach. By using measured acoustic parameters (critical distance, reverberation time) to mathematically model sound propagation, the system achieves accurate noise level estimation at the listener position without physical proximity to the listener.
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 effectively addresses the proximity ambiguity problem by providing accurate noise compensation, ensuring that audio volume adjustments are appropriate for the listener's location, reducing errors in noise estimation and improving audio clarity.
Implementation Method 1
frequency-dependent reverberation times
Data Source
AI summary
Noise compensation method comprising: (a) receiving a content stream including content audio data; (b) receiving first microphone signals from a first device; (c) detecting ambient noise from a noise source location in or near the audio environment; (d) causing a first wireless signal to be transmitted from the first device to a second device, the first wireless signal including instructions for the second device to record an audio segment (e) receiving a second wireless signal from the second device; (f) determining a content stream audio segment time interval for a content stream audio segment; (g) receiving a third wireless signal from the second device, including a recorded audio segment captured via a second device microphone; (h) determining a second device ambient noise signal at the second device location; and (i) implementing a noise compensation method for the content audio data based, at least in part, on the second device ambient noise signal.