Hits every turn for 2-3 turns, then confuses the user.

Supersonic attacks for 2-3 turns, during which it cannot switch out, and then becomes confused.
Confused Pokémon have a 33% chance of hurting themselves each turn, for 1-4 attacking turns (50% chance in Generations 1-6).
The damage received is as if the Pokémon attacks itself with a typeless 40 power Physical attack.
Pokémon with the ability Own Tempo can not be confused.
Pokémon with Soundproof (due to it being a sound-based move) are also immune to Supersonic.

• In Gen 1-5 Supersonic can not affect a Pokémon behind a Substitute