Thunderclap Spell
Prerequisites storm order
Your lightning splits the air, generating a booming shock wave. If your next action is to Cast a Spell that has the electricity trait or deals electricity damage, has no duration, and requires creatures to attempt a saving throw, the force of the spell's lightning creates a thunderclap, in addition to its other effects. Each creature that failed its Reflex save against the spell is Deafened for 1 round, and those who critically failed are also knocked Prone.
Traits
This indicates abilities from the druid class.
An effect with the sonic trait functions only if it makes sound, meaning it has no effect in an area of silence or in a vacuum. This is different from an auditory spell, which is effective only if the target can hear it. A sonic effect might deal sonic damage.
Spellshape actions tweak the properties of your spells. You must use a spellshape action directly before casting the spell you want to alter. If you use any action (including free actions and reactions) other than casting a spell directly after, you waste the benefits of the spellshape action. The benefit is also lost if your turn ends before you cast the spell. Any additional effects added by a spellshape action are part of the spell's effect, not of the spellshape action itself.