Do you think ill later have hassles if my 9 year old ignores me all the time?

Problem now: If you allow your child to "ignore" you at this young age, it seems you already have a problem that will only escalate if you do not establish parameters for acceptable behavior, expectations and consequences.

Provide choices to encourage independence within a framework of boundaries. Distinguish clearly between acceptable and not acceptable behavior Praise good behavior and consider a reward system. Encourage responsibility and assign tasks around the house.

In addition to the other answers, one might have the Ears tested in case the child has some hearing disorder issues.