This paper introduces a new audio and speech broadband coding technique based on the combination of a pulse excitation coder and a standardized parametric coder, namely, MPEG-4 high-quality parametric coder. After presenting a series of enhancements to regular pulse excitation (RPE) to make it suitable for the modeling of broadband signals, it is shown how pulse and parametric codings complemen...

The paper investigates the automatic evaluation of voice-related criteria of speakers with laryngeal cancer using a parametric two-mass model of the glottis. In contrast to previous approaches based on automatic speech recognition, the proposed method allows for a distinct evaluation of voice parameters alone since the underlying feature extraction technologies are based on a modeling of the wh...

This paper describes a speech coder for low bit rates using a parametric representation of voiced excitation waveforms (Glottal ARX) and standard LPC for unvoiced. For efficient compression purposes the excitation and spectrum parameters are quantized with vector quantization (VQ). This has resulted in a glottal vocoder operating at 1320 bits/s and sounding more natural than a standard LPC voco...

A novel method for the excitation of ELF waves in the ionosphere is presented. It utilizes the nonlinear mixing of two groundor satellite-produced radio frequency waves with a compressional Alfv6n wave. Parametric amplification thresholds are estimated to be between 10 and 20 MW peak power for 5-MHz pumps producing waves in the ELF range. Potential applications to ELF communications are discussed.

Transient stimulated Raman scattering is used for the generation of a frequency shifted picosecond light pulse; part of this Raman shifted pulse is subsequently coherently scattered at a material excitation of a second Raman cell. Starting with the second harmonic pulse (tp = 4 ps) of a mode-locked Nd : glass laser system, both the stimulated and the coherently produced pulses have durations of...

It is well known in system identification that, under output feedback control without persistent excitation, the resultant estimate of the process will be biased. In non-parametric identification the estimate is biased towards the negative inverse of the controller. A similar relationship is shown to exist for parametric identification. Indeed, we show the existence of a fundamental sensitivity...