äh

Etymology
Probably natural.

Interjection

 * 1) argh expression of annoyance, anger or frustration

Interjection

 * 1) an exclamation of disgust; yuck, ew, ugh

Interjection

 * 1) uh, er expression of confusion or uncertainty

Interjection

 * 1) eh, meh expression of mild annoyance, frustration, or boredom