Noise cancelling foam, not cut flat but in the shape of the foam in studios over armor can provide safety against sonic weapon attacks.
Sonic weapons are created like an unbound speak and can be used in multiple ways, including earthquake generators.
An added gel layer can provide extra protection absorbing the remaining blow not cancelled fully by the initial defense of the noice foam.
It best to protects the face and vital organs like normal armor, but other areas are also effected, noise foam on the soles feet can protect against acoustic burning or fracturing due to earthquake generators.
The hands also are vital parts that can be easily effected, covers on the back of the hand is needed to protect them from fracturing without hindering hand movements. This is best done with smaller spikes.
The face, especially the teeth are targets the chip easy from sonic weapon fire, so a mask is needed to cover the face from this.
This foam can have an added layer if the acoustics can pass through it, but the reflecting spikes pattern of the absorbing and reflecting acoustic material needs to be retained in the armor.
Sonic weapon shots can feel like itching, burning and at extremes gurgling, like the feeling of stomach hunger, but on unusual parts of the body. Sonic damage can also feel like thumping. Shots at the throat can cause tickling a coughing, shots at chest can produce a similar effects due to sudden air pressure change.
This one is free for the world, future weaponry, future defense.