INPUT ACOUSTIC IMPEDANCE MEASUREMENT OF NEY WITH PULSE REFLECTOMETRY METHOD
Mohammady Talvar Edris, Banoushi Ayoub, Broghany Mohsen · 2016
ARTICLE INFORMATION ABSTRACT Original Research Paper Received 30 January 2016 Accepted 29 March 2016 Available Online 07 May 2016 Investigation of frequency variations of acoustic impedance can play an important role in identification and optimization of a musical instrument. For a simple tube, the input acoustic impedance can be calculated by analytical methods; for complex geometry objects like wind instrument, however, it cannot be simply computed. Therefore, the impedance is measured for wind instruments. This paper is a report of the first experiment for measuring the input acoustic impedance of Ney (an Iranian woodwind instrument). For this purpose, a pulse reflectometer device was made. To ensure correct operation of the reflectometer, in the first step, the input acoustic impedance of a three sections step tube was measured and the results were compared with calculated results using a well-known formula. The acoustic impedances of a Do-ney for various fingering in six case (from all holes closed to all holes opened) were measured. The results show that, contrary to what was seen for flute, the frequencies of minima of the impedance curves have some discrepancies with the frequencies of corresponding playable notes. This may be related to the role of the mouth of the instrument player in producing tones of ney.