Sound Image Localization Using Transfer Function Ratios
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sound image localization apparatuses face challenges in achieving reliable rear virtual sound image localization due to the need for large-scale processing and sensitivity to individual differences in sound propagation and speaker installation angles.
Innovation Solution
A sound image localization apparatus that uses specific filtering calculations involving head-related transfer functions to output rear audio signals from front speakers, employing direct and cross-output sections with filters characterized by dividing head-related transfer functions to simulate spatial propagation from both real and virtual speakers, simplifying calculations and reducing sensitivity to listener position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If crosstalk cancellation is used to achieve accurate sound image localization, then localization precision is improved, but processing complexity increases due to inverse transform calculations
Solution Approach 1:
The patent changes the mathematical approach from inverse transform calculations to simple filter calculations using pre-computed transfer function ratios. Instead of performing complex inverse transforms in real-time, the system pre-calculates the ratios of head-related transfer functions and applies them as simple filtering operations, dramatically reducing processing complexity while maintaining localization accuracy
Solution Approach 2:
The patent performs preliminary calculation of the transfer function ratios (H21/H11, H22/H12, etc.) before the actual sound reproduction. These pre-computed ratios are stored and reused during playback, eliminating the need for complex real-time inverse transform calculations and reducing processing complexity during operation
2Measurement precision
If crosstalk cancellation is used to achieve accurate sound image localization, then localization precision is improved, but reliability decreases due to sensitivity to individual differences and installation angles
Solution Approach 1:
The patent changes the approach from requiring precise individual measurement and exact speaker positioning to using a generalized model that works across different listeners and configurations. By formulating the solution as a system of linear equations with transfer function ratios, the method becomes more robust to variations in individual anatomy and installation angles, improving reliability
Solution Approach 2:
The patent creates a universal solution that works for different listeners and speaker configurations without requiring customization. The transfer function ratio approach provides a generalized model that can be applied across various scenarios, making the system more reliable and less sensitive to individual differences compared to precise crosstalk cancellation
Data Source
AI summary
A sound image localization apparatus comprises an L direct output section that produces an output signal by inputting an audio signal of a rear left audio input channel to a filter having a characteristic obtained by dividing RLD by LD, an L cross output section that produces an output signal by inputting the audio signal of the rear left audio input channel to a filter having a characteristic obtained by dividing RLC by LC, an R cross output section that produces an output signal by inputting an audio signal of a rear right audio input channel to a filter having a characteristic obtained by dividing RRC by RC, an R direct output section that produces an output signal by inputting the audio signal of the rear right audio input channel to a filter having a characteristic obtained by dividing RRD by RD, a first adding section that adds a difference signal between the output signal of the L direct output section and the output signal of the R cross output section to an audio signal of a front left audio input channel, and a second adding section that adds a difference signal between the output signal of the R direct output section and the output signal of the L cross output section to an audio signal of a front right audio input channel.