After reading the thread here about quiet fletching, I started my own testing. My wife was the noise meter.
I would shoot two arrows and she would tell me which of the two was quieter. Then I took the quieter of the two and shot this with another arrow. Fletching shape was limited.
Loudest to Quietest in this order
4 fletch 5" shields
3 fletch 5" shields
4 fletch 5" parabol
3 fletch 5" parabol
3 fletch 4" parabol
4 fletch 4" low profile parabol (homemade)
My splice fletches were noted as being louder then the solid fletch. I think this is because it is diffcult to get the fletch lined up perfect when doing a base splice. Maybe membrain splicing is better in this regards.
This is the feather shape that came out as the quietest. I used the trad parabol shape as a base and reduced the profile height. The highest point is 7/16". Made these by making two sheet metal templates and clamping the fletching in the middle, then burned to shape with a propane torch.
Beman MFX Classic 340 27-3/4" long with 16 grain insert and 250 grain point.
James