4.3. Acoustic compliances
In Eq. (2.72) we showed that a length of tube, rigidly closed on one end (x = 0), with a radius in meters greater than (so that the sidewall friction can be neglected) and less than 10/f (so lateral standing waves are not present) has an input acoustic impedance at the open end equal to
where Z A = Z s /(πa 2), ρ 0 is density of the gas in kg/m3, c is speed of sound in m/s, a is radius of tube in m, k is wave ...