Harmonic coders that synthesize speech without transmitting phase information abandon the benefits of closed-loop parameter estimation via waveform matching. In this paper, we show that effective closed loop parameter estimation can be achieved when a suitable time-scale modification is applied to the speech LP residual in harmonic coders. The concept is demonstrated here specifically for pitch...

We have developed a near-field microwave microscope to locally excite a superconducting film and measure secondand third-order harmonic responses at microwave frequencies. We study the local nonlinear response of a YBa2Cu3O72d thin film grown on a bicrystal SrTiO3 substrate. The location of the bicrystal grain boundary is clearly identified by the microscope through higher harmonic response, an...

The theory of Bloembergen and Pershan for the light waves at the boundary of nonlinear media is extended to a nonlinear two-dimensional (2D) atomic crystal, i.e., a single planar atomic lattice, placed between linear bulk media. The crystal is treated as a zero-thickness interface, a real 2D system. Harmonic waves emanate from it. Generalization of the laws of reflection and refraction give the...

Spherical harmonic analysis has been a widely used approach for spatial audio processing in recent years. Among all applications that benefit from processing, Active Noise Control (ANC) remains unique with its requirement open spherical microphone arrays to record the residual sound field throughout continuous region. Ideally, low delay recording algorithm is desired real-time ANC systems. Curr...

Estimation of spectral envelope in frequency domain allows to avoid some problems of the Linear Prediction (LP) algorithms for voiced speech. We present a low complexity method of spectral envelope estimation from harmonics for low rate coding. The method consists in computing harmonic amplitude spectrum using pitch-synchronous DFT with length depending on voicing, modifying this spectrum outsi...