A method of sampling jitter measurement based on time-domain analytic signals is proposed. Computer simulations and measurements were performed in order to compare the proposed method to the conventional method, in which jitter is evaluated based on amplitudes of sideband spectra for observed signals in the frequency-domain. The results show that the proposed method is effective in that this method: 1) provides good temporal resolution as a result of the direct derivation of jitter waveform, 2) achieves higher precision in measurement of jitter amplitude, and 3) can separate sidebands that originated in sampling jitter from sidebands caused by amplitude fluctuations, while observing the power spectra, because both amplitude fluctuation waveform and jitter waveform can be derived from analytic signals.
Convention Paper 5586

09:30 h
N2 Small-Signal Analysis for Generalized Push-Pull Tube Amplifier Topology – Pierre Touzelet¹, Menno van der Veen² - ¹SEREME, Bondoufle, France; ²Ir Buro Vanderveen, Zwolle, Netherlands

This work is an addition to a previous AES preprint (4643), where a new generalized push-pull tube amplifier topology was introduced, allowing an easy evaluation of maximum output power, optimal primary impedance of the output transformer and the damping factor, by a direct simulation of equations on a computer. But direct simulation is not always the right tool to use when accurate information has to be derived at small input signal. Then the appropriate tool is a systematic use of Taylor's expansions. The aim of this paper is to show how to determine these expansions and which new results and insights can be derived from them, like new stability criteria, output impedance variations, harmonic distortions and effective voltage gains.
Convention Paper 5587

10:00 h
N3 The Automation of Subjective Measurements of Speech Intelligibility in Rooms – Stefan Brachmanski, Wroclaw University of Technology, Wroclaw, Poland

The paper describes the new measurement system and method of speech transmission quality evaluation called “modified intelligibility test with forced choice” (MIT-FC). The MIT-FC method provides fully automated measurement of speech intelligibility of rooms. The listener's task is to selected on computer monitor which of alternative utterances presented him visually was spoken. The computer's program automatically calculates speech intelligibility and the factor of speech quality. The results are compared with RASTI measurements. The measurement system is based on the local computer network and enables to carry out measurements in several places of the room (depending on the size of the local computer network).
Convention Paper 5588

10:30 h
N4 Sound Source Localization Using Sound Intensity Measured by a Three-Dimensional PU-Probe – Ron Raangs, Erik Druyvesteyn, University of Twente, Enschede, Netherlands

With use of a three-dimensional particle velocity and pressure sensor the active sound intensity can be measured. A simple three-dimensional calibration method of such a sensor is described along with different methods for measuring direct particle velocity and active sound intensity in the far field in a reverberating room. The mean sound intensity can be calculated out of the product of the instantaneous pressure and particle velocity, but also out of the calculated direct pressure and direct particle velocity. In case of an ideal situation the sound intensities are the equal in magnitude and direction, differences yield information about the error and can help increase accuracy of measurement.
Convention Paper 5589

11:00 h
N5 AR/ARMA Analysis and Modeling of Modes in Resonant and Reverberant Systems – Matti Karjalainen¹, Poju Antsalo¹, Paulo Antonio Esquef¹, Aki Mäkivirta², Vesa Välimäki³ - ¹Helsinki University of Technology, Espoo, Finland; ²Genelec, Iisalmi, Finland; ³Pori School of Technology and Economics, Pori, Finland

Discrete-time analysis and modeling of reverberant and resonating systems has many applications in audio and acoustics. In a recent paper (AES110, Preprint 5290) we formulated techniques for the estimation of modal decay parameters from noisy response measurements, targeting to systems such as room reverberation and modal decay as well as musical instrument modeling. In this paper we extend the methodology to AR and ARMA modeling of measured responses by all-pole and pole-zero •lters. In addition to an overview of standard techniques we propose a spectral zooming technique that is useful for resolving very closely positioned modes and high-density modal clusters. Sensitivity to background noise is also studied. Application cases are taken from analysis and modeling of room responses, loudspeaker-room equalization, and estimation of parameters for musical instrument modeling.
Convention Paper 5590