KOROTKOFF’S SOUND – ( named after Dr. Nikolai Korotkoff, a Russian Physician,1905) the five phases in the series of sounds heard when taking the blood pressure by using a stethoscope. 1. PHASE 1 – The period initiated by the first faint, clear tapping sounds. These sounds become rapidly more intense. To ensure that they are not extraneous sounds, the nurse should identify at least two consecutive tapping sounds. 2. PHASE 2 – the period during which the sounds have a swishing quality. 3. PHASE 3 – the period during which the sounds are crisper and more intense. 4. PHASE 4 – the period during which the sounds become muffled and have a soft, blowing quality. 5. PHASE 5 – the point where the sounds disappear.