Don,
I glue and sinew mine like you do, natural turkey wing and secondaries. By copying the NA style from the eastern woodland 3 fletch I get perfectly quiet arrow flight. I split, grind the feather and cut it to 6", then glue it down. I then trim the forward and rearward ends to expose the quill for tieing on the sinew. Then I hand trim the fletch with sicsors to about 3/8" height from the shaft and parrallel to it.
My experience with noisy flect is same as crooketarrow, the higher the fletch the more noise. So ya may need to find the compromise your looking for between long and low & shorter and higher. some place in there is your answer.
Not science, just what I found by trial and error.
rich