Université de Neuchâtel

Watch-dictaphone for Automatic Medical Codification

Grassi, Sara ; Heck, P. ; Stadelmann, Patrick ; Cotofrei, Paul ; Dinissen, P. ; Meylan, F. ; Mignot, J.-P. ; Pfeuti, J.-N. ; Piccini, F. ; Geiser, P. ; Biundo, Giuseppina ; Farine, Pierre-André ; Grupp, Joachim ; Stoffel, Kilian

In: Proceedings of the European Signal Processing Conference (EUPSICO), 2008, vol. 16, p. 1-5

This paper describes the development of a voice data recording watch and the accompanying software and hardware needed to build an integrated solution for medical data capture and auto-matic codification. The developed system is used to capture on the stand-alone watch, either by voice recording or by form-filling, the relevant information on the healthcare service being provided. The captured...

Université de Neuchâtel

An Algorithm for Fast Direct Calculation of Quantized LSP Parameters

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the Fifth Bayona Workshop on Emerging Technologies in Telecommunications (COST 254), 1999, p. 158-162

Line Spectrum Pairs (LSP) are commonly used in speech coding for spectral quantization. Usually, the LSPs are first calculated, and then quantized. When scalar quantization is used, computational saving can be achieved by direct calculation of the quantized LSPs, searching zero-crossings on the grid formed by the values of the quantization tables (quantized-domain search). In a previous...

Université de Neuchâtel

Micropower 'Relative Precision' 15 bit A/D Converter

Grisoni, L. ; Heubi, Alexandre ; Grassi, Sara ; Balsiger, Peter ; Pellandini, Fausto

In: Proceedings of the International Conference on Signal Processing, Applications and Technology (ICSPAT), 1995, p. 420-424

State of the art A/D converters are still critical in power-sensitive, battery-operated equipment like hearing aids. In this article, a new approach is presented that features excellent signal quality, 85 dB dynamic range equivalent to a 15-bit output word, 16 kHz sampling rate, 25 μW power consumption, and 0.54 mm2 chip area. Compared to standard components, the enormous power...

Université de Neuchâtel

LSP calculation methods for application to speech coding

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of Signal Processing Workshop (SPW), 1999, p. 61-66

Line spectrum pair (LSP) parameters are commonly used in speech coding for quantization of the speech spectral envelope. Unfortunately, the high computational complexity in the calculation of the LSP is a drawback for both real-time implementation and application in low-power portable devices. In this paper, some techniques for reducing computational complexity of the LSP calculation are given....

Université de Neuchâtel

A Low-Complexity Variable Bit Rate Speech Coder for Portable Storage Applications

Grassi, Sara ; Matthey, M. ; Biundo, Giuseppina ; Dufaux, Alain ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of Signal Processing Workshop (SPW), 2000, p. 7-12

This paper describes ongoing work in the development of a variable bit rate speech coder for storage applications in portable devices. The coder is based on the CELP FS1016, with different algorithmic modifications aimed at reducing the computational complexity. A silence compression scheme was adapted to this coder, to achieve reduction in both the bit rate and the power consumption. The...

Université de Neuchâtel

Optimized real time implementation of spectral analysis and quantization for the CEOP FS1016 speech coder

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International COST 254 Workshop on Intelligent Communication Technologies and Applications, with Emphasis on Mobile Communications, 1998, vol. 254, p. 33-38

The optimized implementation of the CELP FS1016 spectral analysis and quantization block on a DSP56001 is presented in this paper. This implementation can be seen as a preparation for an optimal low power, small size, custom VLSI implementation. The optimization is based on careful algorithmic optimization and study of the fixed-point quantization effects. Algorithmic optimization deals with the...

Université de Neuchâtel

Study of a VLSI Implementation of a Noise Reduction Algorithm for Digital Hearing Aids

Grassi, Sara ; Heubi, Alexandre ; Ansorge, Michael ; Pellandini, Fausto

In: 7th European Signal Processing Conference (EUSIPCO), 1994, vol. 7, p. 1661-1664

A methodology for meeting the tight constraints in the physical realization of functional blocks for digitalhearing aids was applied to the implementation of a noise reduction system based on lattice structures. This methodologyfully exploits the flexibility of custom VLSI design through a good interrelation among all the steps of the design. Theemphasis was placed in the study of the fixed point...

Université de Neuchâtel

A Low Power VLSI architecture with an Application to Adaptive Algorithms for Digital Hearing Aids

Heubi, Alexandre ; Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto

In: 7th European Signal Processing Conference (EUSIPCO), 1994, vol. 7, p. 1875-1878

A new architecture suitable for an effective low power VLSI implementation of a large class of digital signal processing algorithms is presented, which shows to be particularly well-adapted to fulfil the requirements of portable and autonomous microsystems. Starting with the precise specifications of the application algorithms, an appropriate scheduling method is first applied to optimize the...

Université de Neuchâtel

Fast LSP Calculation And QuantizationWith Application To The CELP FS1016 Speech Coder

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto

In: European Signal Processing Conference (EUSIPCO), 1998, vol. 3, p. 1425-1428

Line Spectrum Pair (LSP) representation is used for spectral quantization in the CELP FS1016speech coder, where the LSPs are first calculated, and then quantized using 34-bit non-uniformscalar quantization. In the algorithm proposed in this paper, computational complexity isdecreased by searching the zero-crossings on the grid formed by the values of the quantizationtables. As the actual LSPs are...

Université de Neuchâtel

Influence of GSM speech coding on the performance of text-independent speaker recognition

Grassi, Sara ; Besacier, Laurent ; Dufaux, Alain ; Ansorge, Michael ; Pellandini, Fausto

In: 10th European Signal Processing Conference (EUPSICO), 2000, vol. 1, p. 437-440

We have investigated the influence of GSM speech coding in the performance of a text-independent speaker recognition system based on Gaussian Mixture Models (GMM). The performance degradation due to the utilization of the three GSM speech coders was assessed, using three transcoded databases, obtained by passing the TIMIT through each GSM coder/decoder. The recognition performance was also...