Methods and apparatus for producing directional sound
US5500900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1994 |
| Grant date | Mar 19, 1996 |
| Priority date | — |
| Expiry date | Sep 23, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S2420/01
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Free-field-to-eardrum transfer functions (FETF's) are developed by comparing auditory data for points in three-dimensional space for a model ear and auditory data collected for the same listening location with a microphone. Each FETF is represented as a weighted sum of frequency-dependent functions obtained from an expansion of the measured FETF's covariance matrix. Spatial transformation characteristic functions (STCF's) are applied to transform the weighted frequency-dependent factors to functions of spatial variables for azimuth and elevation. A generalized spline model is fit to each STCF to filter out noise and permit interpolation of the STCF between measured points. Sound is reproduced for a selected direction by synthesizing the weighted frequency-dependent factors with the smoothed and interpolated STCF's.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.