To turn down the volume on your Hatchimal, this feature is only available once your Hatchimal hatched out of its egg.

1. Turn the Hatchimal OFF.
2. Press and hold your Hatchimal's tongue down while you move the power to the ON position. 
3. Now your Hatchimals is in lower volume mode.  Your Hatchimal will stay in half volume until the next time you turn it OFF.
4. To revert your Hatchimal back to full volume, turn OFF the Hatchimal and turn it back ON.