For sound In a drama film, both Diegetic and Non-diegetic sounds are used. Non-diegetic sounds are used to increase the dramatic elements or intensity of a scene since Non-diegetic sounds are used according to the mood of the scene where as Diegetic sounds are used to add emotions or a sensation to the scene since they include either voices of characters or sounds made by objects in the story.
Romantic films often use music as well as non-diegetic sounds in order to create an atmosphere for the audience. The soft, emotive music is used when protagonists are in a intimate movement along with non-diegetic music playing when they begin a relationship with music building when conflict occurs to leading to a breakup. Overall sound is used to parallel emotive sound music, this helps provoke emotion in the audience.
This is why Yusra Farooq explains the reason for choosing the sound track behing her movie.
Although she hasnt used any ''diegetic'' sounds in Demented.
Yair Albeg Wein & Or Kribos – Mephisto’s Lullaby (Xtortion Audio – Epic Halloween Music/Dark Vocal)