Audio Signal Processing for Adaptive Low-Frequency Loudness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Portable devices have limited speaker systems with poor low-frequency performance and human ears perceive low-frequency signals weakly at low loudness levels, leading to inconsistent audio quality.
Innovation Solution
A signal processing method and apparatus that adjusts volume and frequency gains dynamically based on system volume levels, incorporating low-frequency extension and equal-loudness control to enhance audio output across different frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the speaker system size is increased to improve low-frequency performance, then the low-frequency sound quality is improved, but the device size increases which contradicts the portable device constraint
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the volume gain of low-frequency signals based on the current system volume level. When the volume is low, the low-frequency gain is increased to compensate for reduced human ear sensitivity. This software-based parameter adjustment resolves the contradiction by improving perceived low-frequency quality without physically enlarging the speaker system.
Solution Approach 2:
The patent implements dynamics by making the low-frequency enhancement adaptive and dynamic rather than static. The low-frequency volume gain is dynamically adjusted according to the system volume level, creating a responsive audio processing system that adapts to different listening conditions, thereby improving low-frequency perception without requiring a larger physical speaker.
2Manufacturing precision
If the low-frequency volume gain is increased to compensate for reduced human ear sensitivity at low volumes, then the perceived loudness of low-frequency signals is improved, but the overall audio balance may be distorted
Solution Approach 1:
The patent applies feedback by using the system volume level as input to dynamically control the low-frequency volume gain. The audio processing system continuously monitors the current volume state and adjusts the low-frequency enhancement accordingly, creating a closed-loop control system that maintains audio balance while compensating for reduced low-frequency perception at low volumes.
Solution Approach 2:
The patent changes the low-frequency volume gain parameter dynamically based on the system volume level. Instead of applying a fixed gain, the system adjusts this parameter in real-time, increasing low-frequency gain when volume is low and reducing it when volume is high, thereby maintaining overall audio balance while improving perceived loudness across different listening conditions.
Data Source
AI summary
A signal processing method includes: obtaining an audio signal; in response to a first control signal, performing a first processing on the audio signal to obtain a first audio signal, the first processing being used to adjust a volume gain of the audio signal; based on the first control signal, performing a second processing on the first audio signal to obtain a second audio signal, the second processing being used to adjust a frequency gain of the first audio signal; and performing an audio post-processing on the second audio signal.