thick voice; husky voice; hoarse voice
Describes a voice that is rough, deep, or unclear, often due to physical condition or natural quality. Can be used for both temporary hoarseness and a permanently gravelly voice.
I've gotten a hoarse voice from a cold.
voice with a thick accent
Refers to a voice marked by a strong regional or foreign accent, making it sound thick or muddled. Less common than the hoarse-voice sense.
His thickly accented English is hard to understand.
He speaks in a gravelly voice.
Common hybrid spelling using katakana ダミ and kanji 声.
Hiragana-kana mixed spelling; also common.
Kanji spelling using 濁 (muddiness); less common.
Rare kanji form using 訛 (accent); specifically for the accented voice sense.
The ダミ part is from 濁り (にごり, muddiness), referring to an unclear or muddy sound. The exact derivation of だみ is uncertain, but it is associated with a thick or impure quality of voice.