Absolute pitch (AP) is the ability to name a note without any reference, while relative pitch (RP) needs a previous and known tone to recognize such a note. We suggest that AP is due both to environmental impact and physiological particularity. From the responses of 263 musicians including 169 AP we observed that for AP musical environment in childhood was better, the earlier the age of instrumental beginning as compared to RP. The study of otoacustic emissions evoked by a supraliminar stimulation in 183 musicians' ears including 68 AP showed that the echo was significantly greater in cases of AP than in cases of RP.