Hmmmm thats really really noisy . . . Try and grease up all the joints, and also add lube to the motor gears.
If there is vibration in your parts (sheet metal makes noise when vibrated), try to make them more rigid.
You could also use some sound absorbing foam, but just make sure it doesn't block heat escaping from your motors - or they will fry . . .
Robotics would be better but I am just new at this.
But, robots are more expensive and less reliable . . . and that really hurts when selling a mass market product . . .