Acoustic tube reconstruction from noncausal excitation

Algorithms and experimental procedures are presented for the reconstruction of the area function of a nonuniform tube. This reconstruction is performed from acoustics measurements that are taken in response to acoustic excitation of the tube at one end. The novel aspect of the procedure is that it is applicable to the case where the excitation waveform is a noncausal signal, which includes the case of a periodic excitation signal where the fundamental period is much shorter than the acoustic decay time of the tube being measured. Measurements are made of hard-walled pipes of known area as well as of the human vocal tract.