SUBJECTIVE ASSESSMENT OF TEMPOROMANDIBULAR-JOINT SOUNDS

If it could be shown that the human ear was sufficiently sensitive to describe TMJ sounds, there would be no need to use sophisticated elect ronic equipment to analyse the sounds. To test this, the ability of no rmal listeners to distinguish the subtle changes in position, pitch, d uration and latency present in TMJ sounds is measured using triangle t ests to determine the just-noticeable differences. The results suggest that the human ear is a rather poor instrument for describing subtle differences in the position, duration and latency of TMJ sounds, but i s capable of detecting small differences in frequency. It is therefore doubtful that the human ear can distinguish the reciprocal click asso ciated with disc displacement with reduction from clicks due to defect s of form on the basis of their relative position in the envelope of m ovement.