You may want to try and trim the call so it will fit better in the roof of your mouth. If you have a small palate, you may need a smaller call. They do make calls for smaller palates. If this is not your problem, then try to put a little more pressure on the call with your tounge so it will fit tighter against your palate. You also may want to try and move the call a little forward in the palate. Not all calls fit the same in your mouth. Try to find one that fits well and practice. Some people just can't use mouth calls, but if you practice and get used to them, they are not difficult to use.