The Issue: Induced signal susceptibility has been a factor in electronic equipment performance since the dawning of voltage and current. Often referred to as crosstalk, the undesired coupling of one circuit’s signals to another may result in interference that degrades the integrity of either signal. This article examines the testing process prescribed by RTCA DO-160 Section 19 as part of the Electromagnetic Compatibility (EMC) requirements. These requirements evaluate the Equipment Under Test (EUT) tolerance for capacitive and inductive coupling to the EUT or associated cables. The evaluation covers coupling over the power frequency (including harmonics) range, the audio frequency range, and electrical transients.