Where does “sonalh” come from?

sonalh (Old Occitan) comes from Vulgar Latin sonaculum, from Latin sonō, from Proto-Italic *swonaō.

Ancestry of “sonalh”, step by step

Step	Language	Word	Meaning
1	Vulgar Latin	sonaculum	—
2	Latin	sonō	—
3	Proto-Italic	*swonaō	—

sonalh — Etymology, Origin & Word History | Etymology Explorer