adverb (fukushi), adverb taking the 'to' particle, noun or participle which takes the aux. verb suru, onomatopoeic or mimetic
1. in a subdued voice; in undertones; in a whisper; in a mumble; in a murmur
adverb (fukushi), adverb taking the 'to' particle, noun or participle which takes the aux. verb suru, adjectival nouns or quasi-adjectives (keiyodoshi), onomatopoeic or mimetic