expression, noun
deep, threatening voice; menacing tone
Describes a voice that is low, rough, and intimidating, often used by yakuza or tough characters in fiction. The phrase is a fixed expression.
彼はドスの効いた声で「金を出せ」と言った。
He said, 'Hand over the money,' in a deep, threatening voice.
あの俳優はドスの効いた声が特徴的だ。
That actor is known for his menacing tone of voice.
The phrase combines ドス (a slang term for a knife, possibly from どす, an old term for a short sword) with 効いた (effective, working) and 声 (voice), literally 'a voice with the effectiveness of a knife', metaphorically meaning a voice that cuts through with menace.