Cacophony

Cacophony (Japanese: そうおん Noise) is an ability introduced in Generation III that was removed in Generation IV (due to no Pokémon having the ability); it was re-introduced in Generation VI.

In battle
Cacophony makes the the Pokémon immune to sound-based moves. In addition, if the Pokémon uses a sound-based move on the foe, there is a 10% chance that the foe will become confused.