Stereo Audio Signal Processing for 5.1-Channel Virtual Surround

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Solution Overview

Problem

The existing audio playback systems using double-channel audio signals often result in a relatively poor stereo effect due to the lack of spatial immersion, as they only play left-channel and right-channel audio signals without effectively utilizing additional audio channels.

Innovation Solution

The method involves splitting a first stereo audio signal into 5.1-channel audio signals, processing them based on a three-dimensional surround 5.1-channel virtual speaker box, and synthesizing these signals into a second stereo audio signal that can be played on a common stereo earphone or 2.0 speaker, enhancing the stereo effect by simulating a 5.1-channel audio experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a double-channel audio signal is played by a standard stereo playback device, then the playback is simple and compatible with common equipment, but the stereo effect is relatively poor and lacks spatial immersion

Engineering Contradiction:
Improvecompatibility with common playback equipmentVSAvoidstereo effect quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies dimensionality change by converting a 2-channel audio signal into a virtual 5.1-channel surround sound field. The system creates virtual speaker positions in three-dimensional space (front left, front right, center, rear left, rear right) around the listener, transforming the flat stereo playback into an immersive spatial audio experience with depth, width, and height dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses head-related transfer functions (HRTF) as an intermediary to simulate how sound waves interact with the human head, ears, and torso. The HRTF data acts as a mediator that processes the audio signals to create realistic spatial cues, allowing the brain to perceive sound sources as coming from specific directions and distances without requiring actual surround speakers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If 5.1-channel audio signals are processed based on a three-dimensional surround virtual speaker box, then the stereo effect and spatial immersion are significantly improved, but the processing complexity increases

Engineering Contradiction:
Improvestereo effect qualityVSAvoidsignal processing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of a 5.1-channel surround sound system through software processing. Instead of requiring physical surround speakers and complex hardware, the system synthesizes virtual speaker positions and sound fields that mimic the acoustic characteristics of a real 5.1-channel setup, allowing standard stereo headphones or speakers to deliver immersive audio experiences.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transforms audio signals by changing multiple parameters including time delays, amplitude levels, frequency responses, and spatial positioning for each virtual channel. The system dynamically adjusts these parameters based on HRTF data and listener position to create realistic spatial audio effects, converting simple stereo signals into complex multi-dimensional sound fields.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3618461B1Audio signal processing method and apparatus, terminal and storage medium
Publication Date: 2024.11.20 GUANGZHOU KUGOU COMP TECH CO LTD
  • EP3618461B1 patent drawingFigure 1~2
  • EP3618461B1 patent drawingFigure 3~4
  • EP3618461B1 patent drawingFigure 5~6

AI summary

The present disclosure discloses an audio signal processing method and device, a terminal and a storage medium and belongs to the field of audio processing technology. The audio signal processing method includes: acquiring a first stereo audio signal; splitting the first stereo audio signal into 5.1-channel audio signals; obtaining processed 5.1-channel audio signals by processing the 5.1-channel audio signals based on a speaker box parameter of a three-dimensional surround 5.1-channel virtual speaker box; and synthesizing the processed 5.1-channel audio signals into a second stereo audio signal. Since the first stereo audio signal is split into the 5.1-channel audio signals, the 5.1-channel audio signals are processed and synthesized into the second stereo audio signal, and the second stereo audio signal is played by a double-channel audio playback unit, a user may enjoy a 5.1-channel audio stereo effect. Thus, the present disclosure solves the problem in the related art that a relatively poor stereo effect is caused by only playing two channels of audio signals. Further, a stereo effect in audio playback is improved.