Efficient implementation of a structured total least squares based speech compression method

AbstractWe present a fast implementation of a recently proposed speech compression scheme, based on an all-pole model of the vocal tract. Each frame of the speech signal is analyzed by storing the parameters of the complex damped exponentials deduced from the all-pole model and its initial conditions. In mathematical terms, the analysis stage corresponds to solving a structured total least squares (STLS) problem. It is shown that by exploiting the displacement rank structure of the involved matrices the STLS problem can be solved in a very fast way. Synthesis is computationally very cheap since it consists of adding the complex damped exponentials based on the transmitted parameters.The compression scheme is applied on a speech signal. The speed improvement of the fast vocoder analysis scheme is demonstrated. Furthermore, the quality of the compression scheme is compared with that of a standard coding algorithm, by using the segmental signal-to-noise ratio

Epineurial pseudocyst of the intratemporal facial nerve : a case series study

OBJECTIVES: The goal of this case series was to describe the clinical and radiological characteristics of epineurial pseudocysts of the intratemporal facial nerve (EPIFs) and to discuss the relevance in clinical practice. MATERIALS and METHODS: A retrospective case series of 10 consecutive patients with EPIFs identified through computed tomography (CT), between 2009 and 2018. Morphological characteristics, coexisting pathology, facial nerve function, and evolution over time were analyzed. RESULTS: A unilateral EPIF was found in 5 patients (50%) and a bilateral EPIF was found in the other 5 (50%). The largest dimensions were observedin the coronal plane, with an average craniocaudal length of 6.0 mm (range, 3-9 mm). None of the patients presented with facial nervedys function. Growth could not be observed in any of the patients. In 5 cases (33.3%), CT imaging showed a reduced transmastoid access to the facial recess caused by the EPIF. CONCLUSION: All EPIFs in this study were incidental findings. Facial nerve function was normal in all patients. Knowledge of EPIFs is important to perform safe cholesteatoma and cochlear implant surgery and to prevent unnecessary follow-up imaging

Introduction to Total Least Squares and Errors-in-Variables Modeling : Bridging the gap between statistics, computational mathematics and engineering

\emph{Total Least Squares and Errors-in-Variables Modeling : Analysis, Algorithms and Applications}, (Eds. S. Van Huffel, P. Lemmerling), Kluwer Academic Publishers, Dordrecht, The Netherlands, 2002status: publishe

Fast structured Total Least Squares algorithm for solving the basic deconvolution problem

In this paper we develop a fast algorithm for the basic deconvolution problem. First we show that the kernel problem to be solved in the basic deconvolution problem is a so-called structured Total Least Squares problem. Due to the low displacement rank of the involved matrices, we are able to develop a fast algorithm. We apply the new algorithm on a deconvolution problem arising in a medical application in renography. By means of this example, we show the increased computational performance of our algorithm as compared to other algorithms for solving this type of structured Total Least Squares problems. In addition, Monte-Carlo simulations indicate the superior statistical performance of the structured Total Least Squares estimator compared to other estimators such as the ordinary Total Least Squares estimator. FAST STRUCTURED TOTAL LEAST SQUARES ALGORITHM FOR SOLVING THE BASIC DECONVOLUTION PROBLEM NICOLA MASTRONARDI y , PHILIPPE LEMMERLING z , AND SABINE VAN HUFFEL x Abstrac..

Total least squares based subband modelling for scalable speech representations with damped sinusoids

We describe how Total Least Squares (TLS) algorithms can be applied as a powerful and efficient modelling tool for wideband speech. A detailed description in both time domain and frequency domain illustrates how the modelling functions - damped sinusoids - naturally synthesise non-stationary signals. Straightforward implementations of TLS applied to fullband speech are known to be computationally hard and they can suffer from numerical sensitivity. In this paper we introduce a subband approach, which leads to a significant reduction of the computational load with an enhanced numerical stability. Moreover, it enables to control the distribution of the TLS components over the spectral range of the input signal such that perceptual criteria can be incorporated in the modelling scheme. We also address the scalability of our design from smallband speech to high quality audio, and provide evidence for the existence of coupled components in TLS modelled segments.Hermus K., Verhelst W., Wambacq P., Lemmerling P., "Total least squares based subband modelling for scalable speech representations with damped sinusoids", Proceedings 6th international conference on spoken language processing - ICSLP2000, vol. III, pp. 1129-1132, October 16-20, 2000, Beijing, China.status: publishe

Perceptual audio modeling with exponentially damped sinusoids

While a traditional sinusoidal model can be used to represent audio segments, a sum of exponentially damped sinusoids is more efficient to model the transient segments that are readily found in audio signals. In this paper, Total Least Squares (TLS) algorithms are applied to automatically extract the modeling parameters in the Exponential Sinusoidal Model (ESM). In order to turn the SNR optimization criterion of these TLS algorithms into a perceptual modeling strategy we incorporate the psycho-acoustic model of MPEG 1 - Layer 1 into a subband TLS-ESM scheme. This allows us to model each subband in accordance with its perceptual relevance. Informal listening tests confirm that perceptual ESM achieves the same perceived quality as plain ESM while using substantially less components.Hermus K., Verhelst W., Lemmerling P., Wambacq P., Van Huffel S., ''Perceptual audio modeling with exponentially damped sinusoids'', Internal report PSI-SPCH-03-2, K.U.Leuven, ESAT, 16 pp., April 2003, Leuven, Belgium.nrpages: 16status: publishe

Modeling audio with damped sinusoids using total least squares algorithms

We demonstrate that damped sinusoidal modeling can be used to improve the modeling accuracy of current perceptual audio coders. We show that the model parameter estimation can be performed with TLS algorithms, and that a subband modeling approach results in TLS problems that are computationally much more tractable than the fullband approach. Experimental results indicate that subband TLS modeling can be effectively controlled using perceptual criteria.Verhelst W., Hermus K., Lemmerling P., Wambacq P., Van Huffel S., "Modeling audio with damped sinusoids using total least squares algorithms", Total least squares and errors-in-variables modeling : analysis, algorithms and applications, pp. 331-340, Van Huffel S. and Lemmerling P., eds., 2002, Kluwer Academic Publishers.status: publishe