Final answer:
To rectify distorted audio caused by RF current on a microphone cable, a Ground Loop Isolator would be most effective. It disrupts the ground loop, the source of RF current interference, which results in distorted sound. High-pass and low-pass filters and noise gates offer solutions to other audio problems, but not specifically for RF current-induced distortion.
Step-by-step explanation:
In addressing the student's question, the most suitable device to rectify distorted audio caused by Radio Frequency (RF) current on the shield of a microphone cable is an A) Ground Loop Isolator.
The Ground Loop Isolator operates by preventing interference from the grounding system of the audio device, which is often a source of RF current. RF signals can create a 'ground loop', which results in a distorted sound known as 'hum' or 'buzz'. A Ground Loop Isolator breaks this loop, minimizing these adverse sound effects and improving overall sound quality.
On the other hand, high-pass and low-pass filters are utilized to eliminate specific frequencies, they do not target distortions caused by RF current directly. A noise gate can be employed to suppress noise below a defined threshold, but it may not be the optimal solution for RF current distortion as it does not deal with the root cause of the problem.
Learn more about the Ground Loop Isolator