Groper Train: I Wish I Could Stop (1990)

Sinopsis

One morning on a commuter train. A man was listening to music with headphones on, when suddenly, a woman's moans could be heard from the headphones, perhaps due to a crossover line. Next to the surprised man, he found a woman with a flushed face, also wearing headphones. It seems the woman is listening to the crosstalk. Thinking that it might be something to do with her, the man tries to molest her, but she doesn't resist. It turns out that the woman works for a company that broadcasts FM radio, and is conducting an experiment...