I would go for a second -and even a third- opinion. There may not be anything wrong with your child.. The fact is, your child is too small to tell you that he/she is not able to hear anything. You are now totally dependant upon that doctor to diagnose your child. This puts you and your child at risk of being misdiagnosed- such a high cost to your finances and your child’s health.
Make sure the doctors you use for a second opinion do not know each other and are not networked together.
Did your child receive medication? What about shots/ vaccines?