Audio Diffusor Filtering for Externalized Headphone Spatial Sound
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Solution Overview
Problem
Existing audio reproduction systems using headphones fail to accurately simulate the spatial characteristics of audio sources external to the listener due to the lack of acoustic artifacts associated with air propagation, leading to a diminished listening experience.
Innovation Solution
A system and method that utilizes a diffusion filter, delay, and multipliers to process audio data, creating a diffused audio signal that simulates the perception of audio sources external to the listener by manipulating the timing and distance of audio signals, mimicking the effects of air movement and room acoustics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digitally-encoded audio data is processed through conventional audio systems, then the audio signal can be reproduced, but the spatial image cannot be effectively recreated as an external source
Solution Approach 1:
The audio signal is segmented into multiple components: direct sound, early reflections, and late reverberation. Each component is processed separately through different filter banks and delay lines to recreate distinct spatial characteristics, allowing precise control over the spatial image while preserving acoustic artifacts
Solution Approach 2:
The system dynamically adjusts the diffusion filter coefficients and delay times based on the perceived distance of the audio source. This creates a time-varying signal that mimics the natural dynamics of sound propagation in air, enhancing spatial accuracy while maintaining acoustic realism
2Measurement precision
If a diffusion filter is applied to generate filtered audio data, then the spatial diffusion is improved, but the device complexity increases
Solution Approach 1:
Instead of applying full diffusion processing to all frequency ranges and time periods, the system applies diffusion selectively to specific frequency bands and time windows where it most impacts spatial perception. This partial action approach achieves sufficient spatial diffusion accuracy while reducing overall processing complexity
Solution Approach 2:
The diffusion filter bank serves multiple functions simultaneously: it creates spatial diffusion, performs frequency analysis, and generates timing information for the delay elements. This multi-functionality reduces the need for separate processing stages, thereby reducing device complexity while maintaining spatial diffusion accuracy
Data Source
AI summary
A system for processing audio data, comprising a diffusion data filter coupled to a source of digital audio data, the diffusion data filter configured to generate filtered audio data from the digital audio data. A delay coupled to the source of digital audio data, the delay configured to delay the digital audio data by a predetermined amount. A first multiplier configured to multiply the filtered audio data by a distance gain parameter to generate a first intermediate output. A second multiplier configured to multiply the delayed digital audio data by a complementary distance gain parameter to generate a second intermediate output. An adder configured to add the first intermediate output and the second intermediate output to generate an audio output.