Audio Compressor Target Curves to Avoid Boosting Background Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio signal processing technologies, such as dynamic range compression systems, often amplify unwanted background noise in non-professionally produced audio recordings, leading to unpleasant sound quality, as they are designed for professionally produced content and struggle with noise detection and suppression.
Innovation Solution
Implementing a playback volume controller/leveler system that limits automatic gain control (AGC) and dynamic range control (DRC) processing to avoid boosting signals below a specified threshold level, using noise floor estimation and auditory scene analysis to distinguish between wanted and unwanted noise, and applying specific DRC compression curves to prevent noise amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If dynamic range compression systems amplify signals below a threshold level to improve volume consistency, then volume evenness is improved, but unwanted background noise becomes audible
Solution Approach 1:
The system changes the compression parameter (target gain) based on the input signal level. For signals above the threshold, a first target gain is applied to maintain volume consistency. For signals below the threshold, a second target gain (less than the first) is applied to avoid amplifying background noise. This parameter adaptation resolves the contradiction by making the compression effect conditional on signal level.
2Ease of operation
If AGC and DRC processing is applied to all audio signals to maintain consistent volume, then playback consistency is improved, but noise in low-level signals is boosted
Solution Approach 1:
The system applies different processing characteristics to different parts of the audio signal based on their amplitude level. High-level signals receive full AGC and DRC processing for consistency, while low-level signals receive reduced processing to avoid noise amplification. This local differentiation resolves the contradiction by tailoring the processing strength to the local signal characteristics.
Data Source
AI summary
The processing of audio signals during playback is provided, so that audio signals that fall below a specified threshold loudness level are processed to avoid making unwanted background noise audible. N-channel audio is received from a playback volume controller/leveler (101). The level of the audio is compared with a threshold level. If the level is greater than the threshold level, the audio is processed with a first amount of gain in accordance with a first dynamic range control (DRC) compression curve that is tuned for professionally produced audio. If the level is less than or equal to the threshold level, the audio is processed with a second amount of gain in accordance with a second DRC compression curve that is designed to avoid boosting unwanted background noise. After applying the gain to the audio, the audio is sent to a downstream device.