By softer, I assume you mean volume, which is normal when equipment falls in water. Right now, your best option is to fill a small plastic bag or bowl with uncooked rice, make sure the earphone still has a filter on it so nothing can damage the driver, and put the IEMs in the bag (cover completely with rice, don't just lay it on top of the rice). Leave the IEMs for a minimum of 48 hours, but longer is even better. Don't touch them during this time, and the rice will draw the water out of the earphones (hopefully). Important thing is to not use them right now...good luck, hope it works out for you!
For what it's worth, I've done this with my phone and it works perfectly now...