Proceedings of Meetings on Acoustics - ICA 2013 Montreal

T. Ebihara and S. Yoshikawa

Proceedings of Meetings on Acoustics Volume 19, 2013

http://acousticalsociety.org/

ICA 2013 Montreal Montreal, Canada 2 - 7 June 2013 Musical Acoustics Session 4pMU: Measurements, Modeling, and Simulations of Brass Instruments 4pMU7. Nonlinear wall vibration and wave steepening contributing to tonal metallicness and brassiness in a horn Takayasu Ebihara* and Shigeru Yoshikawa​ ​ *Corresponding author's address: YAMAHA Corporation, 203 Matsunokijima, Iwata, 438-0192, Shizuoka, Japan, prawn_taka@yahoo.co.jp It is well known that wave steepening and shock-wave formation due to nonlinear propagation through the bore are responsible for tonal brassiness of brass instruments. On the other hand, penetrating metallic tones are produced by hand-stopping the French horn. The present study demonstrates that the mechanism account for tonal metallicness of the French horn is nonlinear wall vibration of the bell. The measured waveforms of radiated pressure of the stopped tones indicate rapidly corrugating changes, which are not observed in brassy tones. Also, their spectra show much larger amplitudes of higher harmonics than those in normal mezzo-forte playing. The measurement of the wall vibration at the bell in hand stopping demonstrates similar characteristics. These results suggest that the bell wall vibration is responsible for the radiated tone color. Excitation experiments on the bell are carried out to elucidate the mechanism how the higher harmonic vibration is generated in hand stopping. They indicate that wall vibrations over 3 kHz are excited by the superharmonic generation derived from the geometrical nonlinearity of the bell. Moreover, for a direct support to our inference above, sound pressure of the stopped tone radiated when the horn bell is heavily damped will be examined. Published by the Acoustical Society of America through the American Institute of Physics

© 2013 Acoustical Society of America [DOI: 10.1121/1.4799607] Received 22 Jan 2013; published 2 Jun 2013 Proceedings of Meetings on Acoustics, Vol. 19, 035071 (2013)

Page 1

T. Ebihara and S. Yoshikawa

                                                         

                              

                           !         "          !              #         $           %                                     

      

                                                   &  ! '   (                                   !              

  

   )  ! '   *                                +(* ,              -              !                 "   $             . !    -                             

           

  

             /                         

                    !   !               '  0   )  !                                       1         2 ,      3          1! ,!  4!           3   1   ",5' 6$         ",5' ++3$           -   !    /        ",5' 7*$  

               

         ./          ",5' +(7(    !  ,5' +(86       $ 

             7! 4!  9        7:! 4:!  : "                        

         6$ ;     8     !