Onomatopoeia

ガミガミ

being lectured or nagged by a supervisor

アハハ

a cheerful, loud laugh

ウワーン

a child crying loudly

ウギャー

a surprised scream or shriek

ウフフ

chuckling like you have a secret

ペチャクチャ

chatting about frivolous things

ゴニョゴニョ

muttering so people can’t hear you

ペラペラ

speaking a foreign language fluently

オッホン

clearing your throat for attention

クスクス

laughing quietly, unable to hold it in

ゴロゴロ

thundering rumbling or a boulder/rock tumbling down a hill

ザーザー

lots of heavy rain pouring down

バタバタ

cloth lightly flapping in the wind

ピューピュー

strong, continuous, and cold wintry winds

パシャッ

water scattering, splashing forcefully

コポコポ

water bubbling gently

メラメラ

suddenly bursting into flames

サクサク

crispy, specifically crispy food

コロコロ

something small or light quickly rolling (down a hill)

タタタタ

running at full speed