whisper rap 

A rap style popularized by 21 Savage on his song "Don't come out the house" where one of the verses he whispered on. 21 Savage also used this style in the making of "ASMR" from the "I am > I was" album.

Person 1: Ay you heard of whisper rap?
Person 2: Nah bruh what is that?
Person 1: Lemme show you an example
*Person 1 shows "ASMR"
Person 2: Damn, this go hard!

whisper rap by Sotirf Beats January 16, 2019

Whisper rap 

Really low sounding and more quiet rap music. Rappers such as Saf the Artist are known for using this style.

Person 1: bro, what is this?
Person 2: it’s whisper rap, just listen to beat.
Person 1: ayy this go hard!

Whisper rap by NewslangATL January 6, 2023