Ed Sheeran whispered underneath his breath. Is there other way that people whisper?
Quoted from "Ed Sheeran- Perfect"
"Baby, I'm dancing in the dark with you between my arms
Barefoot on the grass, listening to our favorite song
When you said you looked a mess, I whispered underneath my breath
But you heard it, darling, you look perfect tonight"
I wonder how is a whisper underneath a breath.
Does it mean Ed's voice of whisper is lower than his breath?
Is there other way that people whisper? Please show me examples.