AASM Sleep Technologist Practice Test

Common mode rejection describes how a differential measurement system minimizes noise that appears equally on both input leads. When interference affects both lines in the same way, the differential amplifier subtracts one input from the other, canceling out the common noise and preserving the true signal difference. That’s why the statement that best captures this concept is that it reduces noise present on both input leads. The other ideas describe different aspects—signal gain, timing delay, or filter characteristics—not the suppression of identical noise on both inputs.