The oxymoron "tranquil patter" affects this sentence since It implies that the noise of the rain on the windowpane is relaxing.
Explanation:
Oxymoron is a device that uses contrasting words that together create a different meaning for something, tranquil and patter are opposite since one word is relaxing and the other refers to the disturbing activity, within the context it refers how the nature from the heavy storm has diminished to it minimum which is relaxing instead of frightening.
