How do I muffle the sound of an 8 inch ventilation intake.?

I have an eight inch intake to a project space that needs full capacity of the intakes airflow. What can I put on the front end to muffle the noise to the point that you can barely hear it. I don't need eliminate the noise completely but knock it down to the point its not so obnoxiously loud as it is now.|||try putting an elbow on it .