AES Milan 2018
Poster Session P11
P11 - Posters: Measurement
Thursday, May 24, 11:45 — 13:15 (Arena 2)
P11-1 Presence Detection by Measuring the Change of Total Sound Absorption—Michal Luczynski, Wroclaw University of Science and Technology - Wroclaw, Poland
The author of this paper analyzed potential possibilities of human presence detection inside a room based on determining the change in total sound absorption. The change between sound absorption with and without human leads to determine person presence. Limitations of this method were examined: in case of human presence, the change of reverberation time must be greater than measurement uncertainty. Important parameters are a volume of a room, total sound absorption, a frequency characteristic of the measurement signal, signal to noise ratio, etc. These parameters are criteria for assessing the reliability of the detection. Different types of measurement signals and systems were considered and tested. The aim was a maximum simplification of measurement method while keeping the minimum measurement uncertainty.
Convention Paper 9957 (Purchase now)
P11-2 The Evolution of Chirp-Based Measurement Techniques—Mark Martin, Audio Precision - Beaverton, OR, USA; Jayant Datta, Audio Precision - Beaverton, OR, USA; Xinhui Zhou, Audio Precision - Beaverton, OR, USA
Logarithmic chirp signals, also known as exponentially swept sines, have been used to determine the behavior of audio systems for more than two decades. This is done using a nonlinear deconvolution process that evaluates the direct and harmonic responses of a system. Despite the long history of this technique, improvements continue to be discovered and questions remain. Relatively subtle features of these signals are important for making accurate measurements. This paper describes how these signals have been used in measuring audio systems, describes the current state of the art, and clarifies the theoretical foundations and limitations of the technique.
Convention Paper 9958 (Purchase now)
P11-3 A Novel Measurement Procedure for Wiener/Hammerstein Classification of Nonlinear Audio Systems—Andrea Primavera, Universitá Politecnica della Marche - Ancona, Italy; Michele Gasparini, Universitá Politecnica della Marche - Ancona, Italy; Stefania Cecchi, Universitá Politecnica della Marche - Ancona, Italy; Wataru Hariya, KORG Inc. - Tokyo, Japan; Shogo Murai, KORG Inc. - Tokyo, Japan; Koji Oishi, KORG Inc. - Tokyo, Japan; Francesco Piazza, Universitá Politecnica della Marche - Ancona (AN), Italy
Non linear systems identification is a widespread topic and many techniques have been developed over the years in order to identify or synthesize black box models. Among the others, Wiener and Hammerstein structures are two of the more common nonlinear models, and identification techniques based on them are widespread in the literature. The choice of one structure over the other needs some a-priori knowledge. In this paper a novel method to determine if a system has a Wiener or Hammerstein nature is introduced. The method is based on the comparison of frequency responses in linear and nonlinear working region. Some simulated and real test results are reported in order to confirm the validity of the proposed approach.
Convention Paper 9959 (Purchase now)
P11-4 Moving Microphone Measurements for Room Response in Cinema—Paul Peace, Community Professional Loudspeakers - Chester, PA, USA; Harman International - Stamford, CT, USA; Shawn Nageli, NXC Systems - West Jordan, UT, USA; Harman International - Stamford, CT, USA; Charles Sprinkle, Kali Audio - Simi Valley, CA, USA; Harman International - Stamford, CT, USA
Comparison of static multi-microphone measurements are made to moving microphone measurements for the purposes of determining room response and for application of appropriate equalization. Several benefits of moving microphone measurements are shown in this paper including consistency of measurements and the ability to measure interaction of correlated signal from multiple sources without the obfuscation of combing artifacts. It is also shown that moving microphone measurement is consistent with multiple microphone spatial average of sufficient resolution. This paper focuses on the moving microphone technique in the cinema application and experiments conducted were done in a medium sized cinema auditorium.
Convention Paper 9960 (Purchase now)
P11-5 Balloon Explosion, Wood-Plank, Revolver Shot, or Traditional Loudspeaker Large-Band Excitation: Which Is Better for Microphone Measurement?—Balazs Kakonyi, Université du Mans - Le Mans, France; Harman International Industries - Budapest, Hungary; Riyas Abdul Jaleel, Université du Mans - Le Mans, France; Antonin Novak, Université du Mans - Le Mans, France
The work presented in this paper investigates different sound sources used for microphone measurement in an anechoic room. The microphone under test is measured using three different physical impulse-like sources: balloon explosions, sounds created using wood-planks, and revolver shots; and the results are compared with a measurement in which the sound is generated by a loudspeaker excited with a large band swept-sine signal. The frequency response functions of three different commercial microphones are measured and compared with the data provided by the manufacturer.
Convention Paper 9961 (Purchase now)