Surround Sound Virtualizer with Dynamic Range Compression
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Solution Overview
Problem
Conventional surround sound virtualizers face challenges in providing accurate sound localization and sonic performance due to fixed 'sweet spot' requirements, inadequate emphasis on virtualized rear channels, and high processor and memory demands, which limit their effectiveness in generating immersive audio experiences for diverse listener head characteristics and speaker configurations.
Innovation Solution
A surround sound virtualization method and system that employs a simplified filter topology, dynamic range compression, decorrelation, and customizable head-related transfer functions to generate output signals for a pair of physical speakers, ensuring improved sonic performance and accurate sound localization by amplifying rear source inputs nonlinearly and transforming them according to HRTFs, while maintaining low computational requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional surround sound virtualizers are used to generate output signals for physical speakers, then sound localization and sonic performance are provided, but fixed 'sweet spot' requirements and inadequate emphasis on virtualized rear channels limit effectiveness
Solution Approach 1:
The system dynamically adjusts the head-related transfer function (HRTF) based on detected listener characteristics and speaker configuration, rather than using a fixed HRTF. This allows the virtualizer to adapt to different listeners and configurations in real-time, eliminating the fixed 'sweet spot' requirement while maintaining accurate sound localization
Solution Approach 2:
The system changes the parameters of the HRTF based on listener head characteristics and speaker positions. By detecting listener characteristics and adjusting the HRTF parameters accordingly, the system achieves accurate sound localization for diverse configurations without requiring a fixed sweet spot
2Measurement precision
If dynamic range compression is applied to rear source inputs, then improved localization and sonic performance are achieved, but processor and memory demands increase
Solution Approach 1:
The system applies dynamic range compression selectively and partially to the rear channel inputs rather than to all audio signals. This partial application provides the necessary emphasis for accurate rear channel localization while minimizing the additional processor and memory demands that would result from more comprehensive processing
Data Source
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AI summary
Method and system for generating output signals for reproduction by two physical speakers in response to input audio signals indicative of sound from multiple source locations including at least two rear locations. Typically, the input signals are indicative of sound from three front locations and two rear locations (left and right surround sources). A virtualizer generates left and right surround outputs useful for driving front loudspeakers to emit sound that a listener perceives as emitting from rear sources. Typically, the virtualizer generates left and right surround outputs by transforming rear source inputs in accordance with a head- related transfer function. To ensure that virtual channels are well heard in the presence of other channels, the virtualizer performs dynamic range compression on rear source inputs. The dynamic range compression is preferably accomplished by amplifying rear source inputs or partially processed versions thereof in a nonlinear way relative to front source inputs.