Patent ID: 9460728
Filing Date: 2016-10-04
CPC Classification: G10L,H04S

Claim Text:
1. A method for encoding multi-channel Higher Order Ambisonics (HOA) audio signals for noise reduction, comprising steps of decorrelating the channels using an inverse adaptive Discrete Spherical Harmonics Transform (DSHT), the inverse adaptive DSHT comprising a rotation operation and an inverse DSHT, with the rotation operation rotating the spatial sampling grid of the iDSHT, wherein the spherical sample grid is rotated such that the logarithm of the term is minimized, wherein are the absolute values of the elements of Σ W with a row index l and a column index j, and are the diagonal elements of Σ W , where Σ W =W Sd W Sd H and W Sd is a matrix having a size of number of audio channels by number of block processing samples, and W Sd the result of the inverse adaptive DSHT; perceptually encoding each of the decorrelated channels; encoding rotation information, wherein the rotation information is a spatial vector {circumflex over (ψ)} transmitting or storing the perceptually encoded audio channels and the encoded rotation information.