A high-pitched, shrill call is just what is needed sometimes to get the attention of, and spur action by, an otherwise reluctant spring gobbler.
This is where the May Day turkey glass pot call comes in. They can be worked so as to be very loud and raspy. Sometimes they even offer a bit of a whine, sounding like a turkey pleading for someone else to stop by.
As with all pot calls, work it by holding the call lightly, just by the fingertips. That will allow for the best, loudest sound.