Similar sound:
* Snorted
* Gruffly cleared their throat
* Made a noise of disapproval
Similar meaning (disagreement/displeasure):
* Scoffed
* Grunted
* Humph-ed
* Muttered
* Grumbled
* Moaned
More dramatic:
* Fumed
* Riled
* Sputtered
* Frowned
* Scowled
The best synonym will depend on the context of the sentence. For example, if you want to emphasize the sound, "snorted" might be a good choice. If you want to focus on the speaker's disapproval, "scoffed" might be better.