Objective analysis of the singing voice as a training aid.

A new tool for robust tracking of fundamental frequency is proposed, along with an objective measure of main singing voice parameters, such as vibrato rate, vibrato extent, and vocal intonation. High-resolution Power Spectral Density estimation is implemented, based on AutoRegressive models of suitable order, allowing reliable formant tracking also in vocalizations characterized by highly varying values. The proposed techniques are applied to about 1000 vocalizations, coming from both professional and non-professional singers, and show better performance as compared to classical Fourier-based approaches.

Effects of aerosol scattering phase function formulation on point-spread-function calculations.

The quality of the image produced by an outdoor optical system is affected by the presence of atmospheric aerosols between object and receiver. The properties of the point-spread function that result from aerosol particles were calculated by a new Monte Carlo code called MEDIA (an acronym for Modélisation des Effets de Diffusion Inhérents à l'Atmosphère). The influence of the scattering phase function's angular dependence on the irradiance of the focal plane of a detector was studied.

Developmental aspects of infant's cry melody and formants.

This paper deals with the analysis of cry melodies (time variations of the fundamental frequency) as well as vocal tract resonance frequencies (formants) from infant cry signals. The increase of complexity of cry melodies is a good indicator for neuro-muscular maturation as well as for the evaluation of pre-speech development. The variation of formant frequencies allows an estimation of articulatory activity during pre-speech vocalization.

A simple subspace approach for speech denoising.

For pathological voices, hoarseness is mainly due to airflow turbulence in the vocal tract and is often referred to as noise. This paper focuses on the enhancement of speech signals that are supposedly degraded by additive white noise. Speech enhancement is performed in the time-domain, by means of a fast and reliable subspace approach.

A comparative analysis of fundamental frequency estimation methods with application to pathological voices.

One of the basic parameters characterising voiced phonation is the fundamental frequency, named pitch, which is the rate of vibration of the folds. In pathological voices. pitch variations within an utterance are indicative of the patient status.

Multiple scattering from Chebyshev particles: Monte Carlo simulations for backscattering in lidar geometry.

Lidar measurements are often interpreted on the basis of two fundamental assumptions: absence of multiple scattering and sphericity of the particles that make up the diffusing medium. There are situations in which neither holds true. We focus our interest on multiply-scattered returns from homogeneous layers of monodisperse, randomly oriented, axisymmetric nonspherical particles.

Parametric and non-parametric estimation of speech formants: application to infant cry.

The present paper addresses the issue of correctly estimating the peaks in the speech envelope (formants) occurring in newborn infant cry. Clinical studies have shown that the analysis of such spectral characteristics is a helpful noninvasive diagnostic tool. In fact it can be applied to explore brain function at very early stage of child development, for a timely diagnosis of neonatal disease and malformation.

Laboratory simulations of lidar returns from clouds.

The results of lidar measurements on laboratory-scaled cloud models are presented. The lidar system was based on a picosecond laser source and a streak camera. The cloud was simulated by a homogeneous aqueous suspension of calibrated microspheres.

Computerized cry analysis in infants affected by severe protein energy malnutrition.

A new method of computerized cry analysis has been utilized to evaluate the cries of infants affected by severe protein energy malnutrition. We studied 17 Kenian babies affected by severe malnutrition for more than four months (9 cases of marasmus and 8 of kwashiorkor) and a control group of 17 well-nourished babies. The cries of the malnourished children showed lower inter-utterance variability, formants' frequencies and cry score, assigned by the Infant Cry Modulation Assessment Scale.

Transmission of a pulsed polarized light beam through thick turbid media: numerical results.

We present numerical results on the change in polarization state of light pulses transmitted through thick turbid media. These results were obtained with a modified version of a previous Monte Carlo code that takes into account depolarization introduced by multiple scattering. The results have shown that for scattered received power pulse shape, polarization and total received power mainly depend on the transport cross section, σ(d), of the medium.

Monte Carlo calculations of the modulation transfer function of an optical system operating in a turbid medium.

Using a Monte Carlo method, we investigate the effect of a turbid medium on image transmission by means of the modulation transfer function approach. We present results that refer to a medium that consists of a random distribution of water spherical particles in air. We analyze the effect of geometric conditions (medium width and position) and source characteristics (Lambertian, beam emission).

Laboratory simulations of lidar returns from clouds: experimental and numerical results.

The experimental results of laboratory simulations of lidar returns from clouds are presented. Measurements were carried out on laboratory-scaled cloud models by using a picosecond laser and a streak-camera system. The turbid structures simulating clouds were suspensions of polystyrene spheres in water.

Transmission of a pulsed thin light beam through thick turbid media: experimental results.

Experimental results of light pulse transmission through thick turbid media are presented. Measurements have been carried out on polystyrene latex spheres by using a picosecond thin laser beam and a streak camera system. The results show that the shape of the received pulse depends mostly on the transport mean free path and on the absorption coefficient of the medium, indicating that both the absorption coefficient and the asymmetry factor of the scattering function can be obtained from the pulse shape.

Simple inexpensive method of measuring the temporal spreading of a light pulse propagating in a turbid medium.

A simple and inexpensive method of measuring statistical parameters related to the time lengthening arising in the propagation of a light pulse in a turbid medium is presented. The method is based on the repetition of attenuation measurements of a light beam passing through the turbid medium when the absorption coefficient of the medium surrounding the diffusing particles is varied. The measurements are carried out using a cw source and a simple optical receiver with a common photodiode as a detector.

Method of measuring the phase function of a turbid medium in the small scattering angle range.

A method is described for measuring the phase scattering function of a turbid medium in the near forward direction. The method is based on the use of a transmissometer with a variable field of view and is suitable for measurements on natural media, such as water or turbid atmospheres. Some precautions to be taken to avoid the effects of multiple scattering are indicated.

Separation and analysis of forward scattered power in laboratory measurements of light beam transmittance through a turbid medium.

In laboratory measurements of the transmittance of a light beam through a diffusing medium (water plus latex spheres), a distinction between the attenuated beam power and the received forward scattered power was made possible by the use of a transmissometer whose receiver has a variable field of view. The dependence of the received scattered power on the FOV angle and on the medium optical depth was analyzed. The deduced separated contributions of first- and second-order scattering, as well as the total received scattered power, were compared to the results of calculations.