Without seeing the call I would say that you probably have tocup your hands over the end to produce back pressure.
To do this grasp the call near the end with your right hand using your index finger and thumb. Curl your fingers together to form an extension of the call. The call will be between your thumb and index finger right next to your hand. You will then place the left hand alongside the opening in your right hand and cover the end to create a bowl like area for the air to go into. Blow into the call and see if that makes a difference.
If it does then you can work on getting the who cooks for you, who cooks for you all......