Dual Recording Device Noise Filtering via Segmented Frequency Analysis
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Solution Overview
Problem
Conventional IC recorders face challenges in achieving high directivity due to limitations in design and manufacturing costs, leading to noise interference from ambient sounds during audio recording, especially in settings like small concerts where precise audio capture is required.
Innovation Solution
A recording system comprising two devices, one with directional microphones and another with omnidirectional microphones, that perform frequency analysis and noise band detection to filter out noise, allowing for improved audio quality by coordinating their analysis ranges and filter processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a directional microphone with high directivity is used, then audio quality is improved, but device cost and complexity increase
Solution Approach 1:
The audio processing function is segmented between two recording devices: one captures the target sound with directional microphone, the other captures ambient noise with omnidirectional microphone. Each device performs simpler frequency analysis independently, avoiding the need for one device to handle both high-directivity capture and noise cancellation complexity
Solution Approach 2:
A noise detection device (second recording device with omnidirectional microphone) is introduced as an intermediary to specifically detect ambient noise. This intermediary device enables the primary recording device to achieve better audio quality without needing to implement complex noise cancellation algorithms internally
2Measurement precision
If multiple microphones are arranged for directional recording, then directivity is improved, but design freedom and manufacturing cost are constrained
Solution Approach 1:
The microphone array function is segmented across two separate devices. The first device uses a simple directional or omnidirectional microphone configuration, while the second device provides complementary noise detection. This segmentation avoids the need for complex multi-microphone array design and manufacturing within a single device
Solution Approach 2:
The second recording device with omnidirectional microphone serves multiple functions: it acts as a noise reference source for the first device, and can independently function as a separate recording device. This multi-functionality reduces the need for specialized high-cost microphone designs
3Productivity
If noise filtering is performed without frequency analysis coordination, then processing speed is improved, but noise reduction effectiveness decreases
Solution Approach 1:
Frequency analysis is performed preliminarily and independently on audio data from both the first and second recording devices before noise filtering. This preliminary frequency analysis identifies noise bands in advance, enabling efficient targeted filtering that maintains both processing speed and noise reduction effectiveness
Solution Approach 2:
The system creates a frequency domain representation (copy) of the audio data from both devices and performs noise band detection on these copies. This allows noise filtering to be applied to the original time-domain audio data without sacrificing processing speed, while achieving effective noise reduction through frequency domain analysis
Data Source
AI summary
A technology is provided that can obtain two audio data with reduced noise, in a system including independent recording devices. A first frequency analyzer performs first frequency analysis on first audio data for each analysis range and generates first result information indicating the result of the first frequency analysis for each analysis range. A condition determinator determines the analysis range based on a first audio quality of the first audio data. A noise band detector detects a noise band for each analysis range based on the first result information and second result information. A first filter processor generates a first filter for filtering data of a noise band for each analysis range, applies a first filter process by the first filter on first audio data for each analysis range, and generates third audio data.