Yenma's Blue Sphere of Astonishment

You hold a blue orb of energy in your hand and for one round you charge the spell. While charging a loud humming sound is emitted from the orb, any creature within 200 feet can hear it. While charging the orb also emits a bright blue light (50 feet of bright blue light with 50 feet of dim blue light) As you charge the orb gets bigger and louder, and at the start of the next round the ground around you begins to rumble. 

At the start of your next turn (After charging) you choose a creature within range that you can see. You fire a small blue sphere at the target. On hit the target creature take 1d4 force damage. 

Secondly the target creature, and any creature within 30 feet of you upon firing, must make a wisdom saving throw versus your spell save or become stunned for 1 round. (From the sheer disappointment of your spell)