Arthritis and other related joint disorders are, today, the most common nonfatal crippling diseases. In every case these joint diseases involve progressive destruction of the articular cartilage. At present, there is no available noninvasive clinical tool which will permit on-going objective evaluation of the relative degree of damage to the articular cartilage. The recently developed computer-aided, electro-acoustical technique, utilizing the acoustic energy emitted by the joint during active articulation, appears to be a promising noninvasive clinical tool. The recent addition of a three-dimensional spectral history plot graphically presents the extent and location of cartilage in a clinically related form.