I cant do the mouth calls to save my life.
If you buy them at Sporting Good stores that might hold true forever....years back I used to tell people if you want some diaphragm calls go to the Bass Pro shop parking lot close to me because all I've bought there went out the window before I left the parking lot.....All I've encountered took too much air to play. I'm not looking for a diaphragm call that I can call a turkey in the next county with.
If you are not tone deaf and have most of your teeth there is no real reason you can't learn to play the right one....there's the key.
Two words "right one".
Will you go broke before you find it ?....Possibly.
First you need to get the simple basics of a playing a diaphragm call....you put it in your mouth hold it up against the roof of your mouth with your tongue...you start to blow/huff air from your diaphragm.
You're looking for the high pitched beginning of the yelp.....yeeee.....then you just drop your jaw and the rear end awwwk just happens.
Diaphragms are semi automatic.