The original sound was also taken from the restroom of an university, when the toilet is flushed this time. A tremolo was added to change and arrange the frequency to make it sound like it is some kind of rotor spinning underwater. VALENTIN_Alexis_2015_2016_rotor-underwater.wav 聲道:2 類型:wav boat、motor、start、underwater、rotor、engine 船、發動機、開始、水下、轉子、發動機 資料來源:freesound ( https://freesound.org )