Where does “ソニー” come from?

ソニー (Japanese) comes from English Sony, from Latin sonus, from Latin sonō, from Proto-Italic *swonaō.

Ancestry of “ソニー”, step by step

Step	Language	Word	Meaning
1	English	Sony	—
2	Latin	sonus	sound, noise; pitch; speech; tone, character,...
3	Latin	sonō	—
4	Proto-Italic	*swonaō	—

ソニー — Etymology, Origin & Word History | Etymology Explorer