5 species have Soundproof as a hidden ability, 10 as a normal one

Effect, in PokéAPI's words

“Protects against sound-based moves.”

As a hidden ability

Species	Slot	Note
Shieldon	Hidden	Since Generation V
Bastiodon	Hidden	Since Generation V
Snover	Hidden	Since Generation V
Abomasnow	Hidden	Since Generation V
Bouffalant	Hidden

As a normal ability

Species	Slot	Note
Voltorb	Normal
Electrode	Normal
Mr. Mime	Normal
Whismur	Normal
Loudred	Normal
Exploud	Normal
Mime Jr.	Normal
Jangmo-o	Normal
Hakamo-o	Normal
Kommo-o	Normal

Elsewhere in PokéAPI

3 more holders without a page here

Alternate forms and other species that PokéAPI lists with Soundproof.

Kommo O Totem, Voltorb Hisui, Electrode Hisui