Paleontologists excavate the fossil of the Parasaurolophus crest soon after its discovery in Northwest New Mexico in August 1995. The fossil was later taken to St. Joseph Medical Center in Albuquerque, NM, where a three-dimensional computer model of the crest was created by performing a CT scan. A series of about 350 cross sections were taken of the crest at 3mm intervals. The cross sections were loaded in numerical form into a computer in order to reconstruct an undistorted computer model of the crest. Once the size and shape of the air passages were determined with the aid of powerful computers and unique software, it was possible to determine the natural frequency of the sound waves the dinosaur pumped out, much the same as the size and shape of a musical instrument governs its pitch and tone.