1. To speak softly, but loudly, with quite a bit of vibration to the vocal cords, not really caring about being overheard
2. The maximum volume of a whisper
3. When whispering just isn't loud enough
He was mad and tried to be quiet, but his whisper turned into a yellsper as his anger grew.
When a whisper just isn't not loud enough.
I cannot hear your whispering. Would you mind Yellspering?