How the Sound Trial works is you listen to the sound of 3 of the same Pokemon’s cries and figure out which one sounds slightly off/different. Once you’ve figured out all the sounds you’ll face against Totem Exploud. Totem Exploud has the ability Bass Boost, which doubles the power of sound type moves.
Totem Exploud Move set:
Boomburst
Hyper Voice
Flamethrower
Ice Beam