Parametric Equalizer Indexing for Low-Overhead Filter Response Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio processing systems for virtual and augmented reality struggle to efficiently control the magnitude response of audio filters, particularly in dynamic environments, due to high computational requirements and inefficiencies in processing and storage.
Innovation Solution
A system and method using a cascade of shelving filters to create a 3-band parametric equalizer, where gain values are derived from prototype filter parameters and stored in a lookup table, allowing for efficient retrieval and interpolation of magnitude responses for specific control frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a proportional parametric equalizer with cascade of shelving filters is used for accurate magnitude response control, then the audio processing accuracy is improved, but the computing cycles and resources required increase significantly
Solution Approach 1:
The patent pre-computes the magnitude responses of prototype filters and stores them in lookup tables before runtime. During actual audio processing, the system only needs to retrieve pre-computed data and perform interpolation, rather than computing filter responses in real-time. This preliminary preparation resolves the contradiction by shifting computational burden from runtime to offline preparation.
Solution Approach 2:
The patent creates simplified representations of complex filter responses by storing magnitude response data in lookup tables. Instead of maintaining and processing full filter models, the system uses copied and interpolated data from pre-computed tables, reducing computational complexity while preserving essential acoustic characteristics.
2Productivity
If filter magnitude response data is pre-computed and stored in lookup tables, then runtime computing costs are reduced, but storage requirements and data retrieval overhead increase
Solution Approach 1:
The patent segments the frequency spectrum into multiple bands and creates separate lookup tables for different prototype filters (e.g., low-shelving, high-shelving, band-pass). This segmentation allows the system to store and retrieve only the specific filter data needed for current processing requirements, reducing overall storage needs while maintaining processing efficiency.
Solution Approach 2:
The patent designs lookup tables to serve multiple purposes: storing magnitude responses for different prototype filters, supporting various interpolation schemes, and enabling runtime retrieval for different audio processing scenarios. This multi-functionality reduces the need for separate dedicated storage structures for each function.
3Device complexity
If conventional displays and fixed speakers are used for presenting virtual environments, then system simplicity is maintained, but immersion and realism are compromised
Solution Approach 1:
The patent implements dynamic audio processing that adapts filter parameters based on virtual object positions, user head movements, and environmental acoustics. The system continuously adjusts magnitude responses to match the expected acoustic properties of different virtual environments, creating immersive experiences that respond naturally to user actions and environmental changes.
Solution Approach 2:
The patent changes audio signal parameters (frequency response, gain, phase) based on virtual environment characteristics and user position. By dynamically modifying these parameters, the system transforms conventional audio output into immersive spatial audio that reflects the acoustic properties of virtual spaces, enhancing realism without requiring completely new hardware.
Data Source
AI summary
A method of processing an audio signal is disclosed. According to embodiments of the method, magnitude response information of a prototype filter is determined. The magnitude response information includes a plurality of gain values, at least one of which includes a first gain corresponding to a first frequency. The magnitude response information of the prototype filter is stored. The magnitude response information of the prototype filter at the first frequency is retrieved. Gains are computed for a plurality of control frequencies based on the retrieved magnitude response information of the prototype filter at the first frequency, and the computed gains are applied to the audio signal.