Use it to clearly ask for repetition without sounding rude when you didn't understand someone.

Request Clarity

Especially useful in noisy environments where you have trouble hearing others.

Noise Interruption

It's a formal and polite way to object or show surprise without directly confronting someone.

It can subtly express annoyance or take exception to something just said.

Use it when reacting to unexpected or astonishing news or events.

A way to mask your surprise while processing unexpected information.

A polite form of apologizing for a minor mistake or slight rudeness.

Conveys genuine regret when you've realised a misunderstanding or error on your part.