adverb, noun or participle which takes 'suru'
breathily; in a muffled voice
Describes speaking in a breathy, muffled, or indistinct manner, often because the mouth is covered or the speaker is out of breath. Onomatopoeic.
マスクをしたままふがふが話す。
He speaks breathily while wearing a mask.
彼は走った後でふがふがして
He was breathing heavily and speaking indistinctly after running.