![]() ![]() Next, we tried to elucidate the mechanism of using C-C sensor and Ensemble Averaging (EA) method using numerical experiments. When measuring some porous materials, C-C method can measure acoustic impedance as same as using P-P method, and C-C method can do it from 100 Hz to over 10 khz. I reported the possibility of using C-C sensor for measuring acoustic impedance on 12th Western Pacific Acoustics Conference 2015 (WESPAC2015) and International Congress on Acoustics 2016 (ICA2016). C-C sensor has many advantages against two omnidirectional microphones (called P-P sensor) and one omnidirectional microphone and sound velocity (called P-U sensor). We propose using two cardioid microphones (called C-C sensor) for it. of Architecture and Living Design, Nihon Univ.,, Narashinodai, Funabashi, Chiba, Japan, Recently, there is growing need for in-situ impedance measurement of several materials. Elucidation of a mechanism of acoustic impedance technique using two cardioid microphones and ensemble averaging method. The good agreement between predicted values and experimental data of clarity, definition, sound strength, and center time in the auditoriums analyzed indicates that the newly proposed model can be used for design predictions with reasonable accuracy. A semi-empirical model based on the measured values of early and late sound levels is proposed in this work. The experimental results were compared with predictions by classical and existing theoretical models proposed for concert halls and churches. These parameters were spectrally averaged according to the most accepted criteria for sound quality evaluation in auditoriums and were expressed as a function of source-receiver distance. Mono-aural measurements in the frequency range from 125 Hz to 4000 Hz (octave band) were conducted in unoccupied auditoriums according to the standard ISO : Acoustical parameters, namely, the clarity C 80, the definition D 50, the early sound level Le, the late sound level Ll, the sound strength G and the center time Ts, have been estimated through analyzing the impulse responses measured in each auditorium. of Technol., Guangzhou, Guangdong, China) Extensive objective energy-based parameters have been measured in three auditoriums (2 scale models and 1 site survey) in the present study. South, Hunghom, Kowloon, Hong Kong, and Yuezhe Zhao (State Key Lab. ![]() Services Eng., The Hong Kong Polytechnic Univ., Rm. Acoustical energy relations in auditoriums. What are these new methods? What acoustical characteristics can one measure with each method? This presentation describes the different source options to measure room acoustical characteristics in larger spaces. There are new developments by academia and equipment manufacturers, as well as improvements on older methods. 5, San Francisco, CA 94104, From sine sweeps to maximum-length sequence (MLS) type signals, balloon explosions to the yachting cannon, options to measure room acoustics in large venues have increased over the past couple of decades. Holst (Charles Salter Assoc., 130 Sutter St., Fl. Room acoustic measurement techniques for large venues (greater than 10,000 cubic meters) in Jason R. The measured directivity of this Dodec meets the standards for omnidirectionality at all frequencies. The Dodec was evaluated in an anechoic chamber. This paper outlines a simple and inexpensive Dodec loudspeaker designed, constructed, and evaluated using ISO 140 and ISO 3382 standards as reference as part of an independent coursework. Commercially available omni-directional loudspeakers are not economically efficient for some purposes. Dodec is a good approximation of a point sound source. The omni-directionality of this sound source makes it mainly applicable in room acoustical and sound insulation measurements and research as it can excite and saturate the room as much as possible. Woolworth (Roland, Woolworth & Assoc., Oxford, MS) Dodecahedron loudspeaker (Dodec) is an omni-directional sound source in the shape of a 12-sided loudspeaker with each side being a pentagon. of MS, NCPA, 145 Hill Dr., University, MS 38677, and David S. Design, construction, and evaluation of an omni-directional loudspeaker (Dodecahedron). Woolworth, Cochair Oxford Acoustics, 356 CR 102, Oxford, MS Contributed Papers 8:30 4aAA1. Session 4aAA Architectural Acoustics: Assorted Topics in Architectural Acoustics I Shinsuke Nakanishi, Cochair Department of Engineering, Hiroshima International University, 5-1-1, Hiro-koshingai, Kure, Japan David S. ![]() ![]() 1 THURSDAY MORNING, 1 DECEMBER 2016 LEHUA, 8:30 A.M. ![]()
0 Comments
Leave a Reply. |