adverb, adverb taking the 'to' particle
Mimics the sound of a frog croaking. Often used adverbially with と or as a standalone sound effect.
池のそばでカエルがケロケロと鳴いていた。
Frogs were croaking by the pond.
adverb, noun or participle which takes 'suru'
robotic auto-tune effect
Colloquial onomatopoeia for a robotic, auto-tuned vocal sound, often used in music or voice effects. Can be used as a する verb.
彼の声がケロケロしていて、まるでロボットみたいだ。
His voice sounds robotic, just like a robot.