I made a custom swing sound for Phate3's Dragonslayer. It's cool that each weapon can have its own swing and impact sounds I guess. I used the large weapon swing from DeadlyReflex and modified it a bit in Audacity to make it sound like you're swinging a very large hunk of metal. It won't replace any vanilla sounds, this gives the Dragonslayer its own swing sound (new sound record).
You need Phate3's Dragonslayer (two handed axe animations version NOT supported, download a two handed sword idle replacer like this one if the vanilla idle bothers you) for this to work. When asked to overwrite the .esp, click Yes.