Would a spellcaster be able to whisper verbal spell components?

@ChrisPerkinsDnD Would a mute spellcaster be able to do verbal spell components using only an airy whisper? As in no vocal-fold vibration?

— Ryan Keizer (@qridproqro) April 17, 2016

DM's call. In my campaign, a mute wizard's spell repertoire would not include spells with verbal components. https://t.co/LVK7VKXKfn

— Christopher Perkins (@ChrisPerkinsDnD) April 17, 2016