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This paper focuses on high-fidelity multichannel audio modeling based on an enhanced adaptation of the well-known sinusoidal plus noise model (SNM). Sinusoids cannot be used per se for high-quality audio modeling because they do not represent all the audible information of a recording. The noise part has also to be treated to avoid an artificial sounding resynthesis of the audio signal. Generally,...
A method is presented for restoration of noisy bandlimited archived speech records. Speech is modeled with a formant-tracking linear prediction (FTLP) model of the spectral envelope and a harmonic noise model (HNM) of the excitation. The time-varying trajectories of the parameters of the LP and HNM models are tracked with Viterbi classifiers and denoised with Kalman filters. A frequency domain pitch...
This paper presents a method for the classification of nonlinear systems through the study of the free oscillations in the time-frequency plane, when the measured data are affected by noise. Nonconservative SDOF (Single Degree Of Freedom) oscillators described by a nonlinear second order differential equation are considered. The nonlinearity is due to a nonlinear function of the state variable, which...
The main purpose of this paper is to provide some additional insight into the several methods of cochannel blind signal separation that are based on the established concept of Independent Component Analysis (ICA). We compare published versions with a robust algorithm that has been devised and developed by the author. Most ICA algorithms are based on maximising the magnitudes of auto-cumulants and/or...
This paper addresses the problem of detecting the presence of multiplicative noise, when the information process can be modelled by a parametric AR process. A suboptimal detector based on higher-order cumulante (HOC) is studied. This detector consists of filtering the data by the fitted AR filter. HOC of the residual data are shown to be efficient for the detection problem.
In many applications, very fast methods are required for estimating and measurement of parameters of harmonic signals distorted by noise. This follows from the fact that signals have often time varying amplitudes. Most of the known digital algorithms are not fully parallel, so that the speed of processing is quite limited. In this paper we propose new parallel algorithms, which can be implemented...
In expressive TTS and voice transformation systems, implantation of expressive prosody derived from external out-of-domain sources often leads to extreme pitch modification that compromises the naturalness of the synthesized speech.
This paper describes the time-domain bandwidth extension (TBE) framework employed to code wideband and super-wideband speech in the newly standardized 3GPP EVS codec. The TBE algorithm uses a nonlinear harmonic modeling technique that incorporates principles of time-domain envelope-modulated noise mixing. At 13.2 kbps, the super-wideband coding of speech uses as low as 1.55 kbps for encoding the spectral...
The ability to estimate the number of words spoken by an individual over a certain period of time is valuable in second language acquisition, healthcare, and assessing language development. However, establishing a robust automatic framework to achieve high accuracy is non-trivial in realistic/naturalistic scenarios due to various factors such as different styles of conversation or types of noise that...
In this paper, we use unconstrained frequency estimates (UFEs) from a noisy harmonic signal and propose two methods to estimate and track the pitch over time. We assume that the UFEs are multivariate-normally-distributed random variables, and derive a maximum likelihood (ML) pitch estimator by maximizing the likelihood of the UFEs over short time-intervals. As the main contribution of this paper,...
Source localization has been studied in the spatial domain using differential geometry in earlier work. However, parameters of the sensor array manifold have hitherto not been investigated for source localization in spherical harmonics domain. The objective of this work is to represent and model the manifold surface using differential geometry. The system model for source localization over a spherical...
In ultrasound, second harmonic imaging is usually preferred due to the higher clutter artifacts and speckle noise common in the first harmonic image. Typical ultrasound use either one or the other image, applying corresponding filters for each case. In this work we propose a method based on a joint sparsity model that fuses the first and second harmonic images while performing clutter mitigation and...
BSIM4 model is not suitable for distortion analysis of circuits with bias point VDS = 0, such as passive mixers and RF switches, due to discontinuities in higher order derivatives. Surface potential based PSP model has continuous derivatives to at least third order, and is therefore suitable for intermodulation products simulation. This paper presents the BSIM4 to PSP model conversion flow and comparison...
In single-channel speech enhancement the spectral amplitude of the noisy signal is often modified while the noisy spectral phase is directly employed for signal reconstruction. Recently, additional improvement in speech enhancement performance has been reported when the noisy phase is modified. In this work, we propose a Bayesian estimator for phase of harmonics given the noisy speech. The proposed...
This paper focuses on the problem of single-channel noise reduction in a transient noise environment for speech enhancement application. A typical speech enhancement algorithm requires an estimate of the noise statistics. However, the problem of noise estimation is challenging when the statistics of the noise vary significantly with time. By exploiting the fact that for speech signal most of the energy...
Problems of spectral estimation of parameters of signal beats in the 3D terahertz FMCW radar are discussed. It is claimed that these problems are due to short time of observation, the low resolution of the classical spectral methods and significant noise that prevents from using parametric methods. Possibilities of using integral-differential harmonic oscillation properties for a variety of discrete...
Single-tone X-parameters-based models are time-invariant non-linear mappings, where the output is a multi-harmonic vector mapping of the incident and scattered waves under periodic steady-state conditions. An envelope simulation combines aspects of both the frequency and time domains, where the input waveforms may be represented as discrete carriers in the frequency domain and the modulation envelopes...
This paper presents a 2.4 kbps harmonic+noise coder with improved transient speech performance. The coder operates in either the steady mode or the transient mode. A predictive phase model is proposed for the efficient encoding of phase information in steady mode. In this model, the normalized frequency deviations are used to minimize the phase prediction errors. A polynomial is fitted to the set...
Single-channel noise reduction for speech enhancement is often applied in cellular and in hands-free telephones. For speech distortions to be minimal, single-channel systems based on spectral subtraction cannot entirely eliminate environmental noise. A relatively high spectral noise floor has to remain in the speech signal. For further reduction of annoying noise components, pitch-adaptive post-filtering...
ECG signals are corrupted by several kinds of noise and artifacts, which negatively affect any subsequent analysis. In the literature, the only approach that can handle any noise and artifacts corrupting the ECG is linear time-invariant filtering. However, it suffers from some important limitations regarding effectiveness and computational complexity. In this paper we propose a novel framework for...
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