Any call will get a response at times - to me I like use what sounds as if it belongs to the flock.
I think High Pitch calls are more of a gimic to suck more money out of you! But then again if a high ptiched call gives you the confidence you need by all means use it!
Pitch does have an important place in my calls - squeals do not...
Drury boys started it with their high frequency calls and now HS Strut seems to be following with that Squealin' Hen.
Just my buck 2.20!
JW