Stereo Depth Processing for Immersive Audio Rendering

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Solution Overview

Problem

Surround sound systems require multiple speakers to create an immersive audio experience, which can be costly and impractical for many setups, while attempts to approximate this effect with stereo systems fall short in providing an immersive experience.

Innovation Solution

A depth processing system that uses stereo speakers to manipulate phase and amplitude information, allowing for the creation of immersive audio effects by simulating sound sources at varying depths, effectively rendering audio along a listener's median plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If surround sound systems use multiple speakers arranged around the listener, then immersive audio experience is improved, but device complexity and cost increase

Engineering Contradiction:
Improveimmersive audio experienceVSAvoidnumber of speakers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by manipulating the temporal and phase dimensions of audio signals rather than adding spatial dimensions through multiple speakers. The system uses phase modulation and time-delay processing on stereo signals to create depth perception, effectively transforming a 2D stereo problem into a 3D spatial audio experience through signal processing in the time and frequency domains.

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

Solution Approach 2:

The patent replaces the mechanical arrangement of multiple physical speakers with electronic signal processing mechanisms. Instead of physically positioning speakers around the listener to create surround sound, the system uses digital signal processing techniques including phase modulation, time-delay adjustment, and spectral manipulation to simulate spatial audio effects from a stereo speaker configuration.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If stereo systems are used to approximate surround sound effect, then device complexity is reduced, but immersive audio experience deteriorates

Engineering Contradiction:
Improvenumber of speakersVSAvoidimmersive audio experience
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs parameter changes by dynamically adjusting multiple signal processing parameters including phase differences, time delays, gain ratios, and spectral characteristics. The system continuously analyzes the stereo input signals and modifies these parameters in real-time to create depth perception and spatial audio effects, transforming ordinary stereo playback into an immersive experience through sophisticated parameter manipulation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by making the audio processing adaptive and time-varying rather than static. The system continuously monitors the input stereo signals and dynamically adjusts processing parameters based on the content being played. This includes real-time phase modulation, adaptive time-delay adjustment, and dynamic gain control that responds to the temporal characteristics of the audio signal, creating a living, responsive spatial audio effect.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2661907B8Immersive audio rendering system
Publication Date: 2019.08.14 DTS INC(US)

AI summary

A depth processing system can employ stereo speakers to achieve immersive effects. The depth processing system can advantageously manipulate phase and/or amplitude information to render audio along a listener's median plane, thereby rendering audio along varying depths. In one embodiment, the depth processing system analyzes left and right stereo input signals to infer depth, which may change over time. The depth processing system can then vary the phase and/or amplitude decorrelation between the audio signals over time to enhance the sense of depth already present in the audio signals, thereby creating an immersive depth effect.