Patent ID: 8971551
Filing Date: 2015-03-03
Classification: G10H,G10L,H04R

Abstract:
1. A virtual bass generation method, including a step of preprocessing samples of a sub-banded, CQMF (complex-valued quadrature mirror filter) input audio signal to generate critically sampled audio indicative of content of a set of low frequency sub-bands of the input audio signal, and including steps of: (a) performing harmonic transposition on the critically sampled audio to generate transposed data indicative of harmonics, wherein the harmonics are expected to be audible during playback of an enhanced version of the input audio which includes said harmonics; (b) generating an enhancement signal in response to the transposed data; and (c) generating an enhanced audio signal by combining the enhancement signal with the input audio signal, wherein the harmonic transposition performed in step (a) employs combined transposition such that the harmonics include a second order harmonic and at least one higher order harmonic of each of the low frequency components, and such that all of the harmonics are generated in response to frequency-domain values determined by a single, common time-to-frequency domain transform stage, and a subsequent inverse transform determined by a single, common frequency-to-time domain transform stage is performed.