公开(公告)号：US20140105419A1

公开(公告)日：2014-04-17

申请号：US14107960

申请日：2013-12-16

Applicant: STMicroelectronics, Inc.

Inventor： Earl Corban VICKERS

IPC: H03G3/00

CPC classification number: H03G3/00 ,  H04R3/04 ,  H04R5/04 ,  H04R2430/03

Abstract: Psychoacoustic bass audio signal enhancement can be accomplished using a monotonic, asymmetric polynomial distortion. A non-linear process applies a monotonic, asymmetric polynomial distortion function that has continuous first and second derivatives to generate even and odd harmonics of missing fundamental frequencies. This polynomial distortion produces the desired psychoacoustic effect with a fairly rapid roll-off so as to avoid unpleasant aliasing. Moreover, the lack of first-order discontinuities prevents clicks or glitches.

Abstract translation: 使用单调，非对称多项式失真可以实现心理声学低音音频信号增强。 非线性过程应用具有连续第一和第二导数的单调，非对称多项式失真函数，以产生缺失基频的均匀和奇次谐波。 这种多项式失真产生所需的心理声学效应，相当快速的滚降，以避免不愉快的混叠。 此外，缺乏一级不连续性可以防止点击或毛刺。

公开(公告)号：US20130332498A1

公开(公告)日：2013-12-12

申请号：US13898428

申请日：2013-05-20

Applicant: STMICROELECTRONICS, INC.

Inventor： Earl Corban VICKERS

IPC: G06F17/14

CPC classification number: G06F17/142 ,  G06F17/156 ,  H03H17/0213 ,  H03H17/0294

Abstract: Embodiments are directed to efficient frequency-domain implementations of time-varying FIR filters. More specifically, time-varying FIR filters according to embodiments exploit the duality of the fast Fourier transform that windowing in the time domain equals convolution in the frequency domain. In one embodiment, convolution of the output of the FIR filter and a desired windowing function is performed in the frequency domain instead of taking the output of the FIR filter in the frequency domain, converting this output the time domain via an IFFT, and then windowing this output in the time domain before again converting back to the frequency domain. As long as the windowing function has certain characteristics, then the time-varying FIR filter is computationally efficient and introduces minimal audible artifacts into the output of the filter. Concepts described herein are discussed in terms of audio signals and systems but are not limited to audio signals and systems.

Abstract translation: 实施例涉及时变FIR滤波器的有效频域实现。 更具体地，根据实施例的时变FIR滤波器利用快速傅里叶变换的二元性，其在时域中的加窗等于频域中的卷积。 在一个实施例中，在频域中执行FIR滤波器的输出和期望的加窗函数的卷积，而不是在频域中获取FIR滤波器的输出，通过IFFT将该输出转换成时域，然后开窗 此输出在时域再次转换回频域。 只要窗口函数具有一定的特性，则时变FIR滤波器在计算上是有效的，并且将最小的可听见的伪像引入到滤波器的输出中。 根据音频信号和系统讨论本文描述的概念，但不限于音频信号和系统。