Final answer:
To auscultate the NB heart rate, use a stethoscope and place it on different locations on the chest, such as the antecubital region. Gradually release air from an inflated cuff placed around the patient's arm to listen for the Korotkoff sounds, which indicate the heart rate.
Step-by-step explanation:
Determining the heart rate of a newborn (NB) through auscultation involves using a stethoscope to listen to the sounds produced by the heart. The stethoscope is typically placed on different locations on the chest to listen to various heart valves. One common placement is the antecubital region, which is the front of the elbow. By gradually releasing air from an inflated cuff placed around the patient's arm, the clinician can listen for the Korotkoff sounds, which indicate the heart rate.