Electrical interference can best be prevented if which of the following actions is taken?

Preventing electrical interference is crucial for obtaining accurate and reliable sleep study data. When the impedances of input electrodes are similar, it ensures that the signals being recorded are consistent and comparable. This homogeneity helps reduce the likelihood of noise and artifacts that can be introduced by discrepancies in electrode properties. A consistent impedance allows for a more stable recording environment and minimizes the potential for interference from external electrical sources.

In sleep studies, where physiological signals such as EEG, EOG, and EMG are captured, having similar impedances across electrodes ensures that the signals remain clear and interpretable. This is particularly important, as variations in impedance can lead to differential effects on signal quality, potentially introducing unwanted noise that complicates analysis.

While using filters and grounding techniques can help manage interference, the fundamental principle of maintaining similar electrode impedance directly impacts the quality of the recorded data most effectively.