An onomatopoeia indicating a popping or booming sound; commonly used as 'pān to' to emphasize a sudden loud noise or impact.
突然ドアがパーンと閉まって、みんな驚いた。
Suddenly the door slammed with a bang, and everyone was startled.
花火が夜空でパーンと破裂した。
The fireworks burst with a loud bang in the night sky.
彼は封筒をパーンと机の上に置いた。
He slapped the envelope down on the desk with a snap.