muffled voice; thick voice
Describes a voice that sounds unclear, as if coming from behind something, often due to a mask, a closed door, or emotional suppression.
Speak in a muffled voice through a mask.
I heard a muffled voice from the next room.
Kanji spelling using 籠; acceptable but less common than the kana form.
From the verb こもる (to be shut in, to be muffled) in its past attributive form modifying 声 (voice).