こつんとwith a bump, with a clunk

窓(まど)に小石(こいし)がコツンと当(あ)たりました。

A small stone hit the window with a clunk. {with a bump, with a clunk}

父親(ちちおや)に軽(かる)くゲンコツでコツンと殴(なぐ)られた。

I was lightly hit on the head with a fist by my father, with a clunk. {with a bump, with a clunk}

先生(せんせい)に頭(あたま)を軽(かる)くコツンと叩(たた)かれて目(め)を覚(さ)ましました。

I woke up after the teacher lightly bumped my head with a clunk. {with a bump, with a clunk}

ボンネットに小(ちい)さな氷(こおり)の粒(つぶ)がコツンと当(あ)たり、傷(きず)がついた。

Small pellets of ice hit the bonnet with a clunk, causing a scratch. {with a bump, with a clunk}

空(そら)から降(ふ)ってきた雹(雹)が頭(あたま)にコツンと当(あ)たって少(すこ)し痛(いた)かったです。

The hail that fell from the sky hit my head with a clunk and it hurt a bit. {with a bump, with a clunk}