You channel magical energy into the target weapon, and the air around it faintly hums each time you strike a blow, as the impact is absorbed into the weapon. If a creature is wielding the weapon at the end of its turn, the weapon discharges a burst of sound targeting one creature adjacent to the wielder (if any). The sonic damage this deals is equal to the number of successful Strikes with the target weapon that the wielder made that turn (to a maximum of 4 sonic damage if the wielder hits with four Strikes).
Heightened (+2) The sonic damage increases by 1 per Strike (and the maximum damage increases by 4).
Traits
An action with this trait requires a degree of mental concentration and discipline.
You must physically manipulate an item or make gestures to use an action with this trait. Creatures without a suitable appendage can't perform actions with this trait. Manipulate actions often trigger reactions.
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.