Musical instruments that start with the letter I include the igil, ipu, Irish uillean, Irish bouzouki, ichigenkin, inci, iya, itotele and istarski mih. The instruments originate from countries ranging from Cuba and Ireland to Croatia, Japan and the Philippines.
Bessel's functions are often used in acoustics for describing circular membranes behaviour (exploited by most of the musical instruments). They are the solutions of the wave equations using polar coordinates. Set the properties of the membrane Bessel's functions describe the vibrational modes of the membrane.
Beno Zerr Â· ENSTA Bretagne. Bessel functions are used to solve in 3D the wave equation at a given (harmonic) frequency. The solution is generally a sum of spherical bessels functions that gives the acoustic pressure at a given location of the 3D space.