Institute of Industrial Science Development of prediction methods Numerical analysis, Scale model experiment Room acoustic design Auditoria, Open-type classrooms Acoustic measurement Sound propagation, Sound insulation and absorption Development of sound field simulation 6 channel recording-reproduction system Subjective evaluation Concert halls, Living environments, Public spaces, other small spaces such as a car cabin -Toward a better sound environment- Mathematics and physics for leading edge acoustics Mathematics and physics for leading edge acoustics SAKAMOTO LAB. Advanced Mobility Research Center http://www.acoust.iis.u-tokyo.ac.jp Applied Acoustic Engineering Department of Architecture, Graduate school of Engineering Mathematics and physics for leading edge acoustics Welcome to aural demonstration using sound field simulator! Acoustic laboratory Ce-101 is important for our quality of life. Our laboratory is making acoustic researches through prediction/measurement of physical aspects of sound and evaluation of psychological/ physiological effects of sound on man, in order to contribute to creation of safe and comfortable acoustic environment. Unified representation of room acoustic parameters Diffuse Non-diffuse 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Time Amplitude p = 1 Noise Exp 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Time Amplitude p = 0.3 Noise Exp 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Time Amplitude p = 0.5 Noise Exp 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Time Amplitude p = 0.1 Noise Exp 0 0.2 0.4 0.6 0.8 1 0.75 0.8 0.85 0.9 0.95 1 Time Amplitude p = 0.01 Noise Exp Mouth simulator Mouth simulator Equalizer Power Amp. Mic. Amp. Data recorder Mixer (12ch.to 6ch.) Real time convolver Mic. Amp. 1.6m SP. SP. SP. SP. SP. SP. SP. SP. SP. SP. Equalizer Power Amp. Mic. Amp. Data recorder Mixer (12ch.to 6ch.) Real time convolver Mic. Amp. 2.0m SP. SP. SP. SP. SP. SP. SP. SP. SP. SP. SP. SP. Impulse responses (6-channel respectively) 6-ch. Microphone system 6-ch. Microphone system 6ch. Loudspeakers In the anechoic room A In the anechoic room B Impulse responses (6-channel respectively) To room B To room A S S S S P P . . S S S S P P . . For speech transmission M u t s i u l t t R e a l t m e c o n v o v e r M c . A m p . u t s i u l t r R e a l t m e c o n v o v e r M i c . A m p . P P Driver-seat Passenger-seat Sound field evaluation in a car cabin Numerical dummy-head Human source directivity , 2 +1 4 ! + ! cos , = , = =0 Expression of directivity using spherical harmonic expansion n=0 n=4 n=8 Hearing directivity Measurement Numerical analysis Prediction of Head-Related Transfer-Function