Your voice is too much for normal people and smart animals to comprehend. Whenever you speak, any being that isn't godlike or demi-godlike that can hear you over a 60 Foot radius that isn't blocked behind sound resistant cover takes Sonic damage and has to make a Constitution saving throw or suffer temporary Deafness and one round stun. People who succeed the con save take half damage and are immune to the effects (despite slight ringing and blood in the ears.)
However, you have since long forgotten how it felt to properly move your mouth in the proper way to speak, every time you try to speak, you must make DC 13 Constitution saving throw to use your voice properly and a DC 13 Dexterity saving throw to control how loud you speak. On fail of Con save, you don't make any noise, and on fail of Dex save, you cant control how loud you speak, forcing you to roll a d2 to determine how loud you speak.
The DC for the deafness and sonic damage depends on how loud you speak, ex:
Whisper : DC 14 , d6 Sonic damage
Loud : DC 16 , 1d12 Sonic damage
However, whenever you use this you take equal damage towards yourself due to how unstable your vocal chords are (without a certain SOMEBODY) and you are unable to speak (use this ability) for the rest of the day, and you gain 1 fatigue.