When someone is impressed by something, or taken aback, they will sometimes make a noise that is usually typed out as, “Oof!” However, the “f” isn’t always vocalized. Sometimes it’s just a flow of air that follows an “oo” sound. So, the “oof” sound isn’t necessarily a word, but a sound in an of itself - like a sigh, a huff, or a scoff.
Imagine, if you will, someone seeing a beautiful car. They might say, “Oof! Look at that car!”
If you were to transcribe that sentence, what word would you use to describe the “oof” sound?