Scratchy Sound Effects in Doom

[Blades]

I've loaded up my old W98 Pentium to play some old PC games. It works fine, and has onboard FM synthesis, however sound effects in Doom, and only sound effects in Doom, are very scratchy. Music is fine, Quake is fine etc. What could be the cause? I used all the default settings in the setup. This is with the original DOS client.

[EyeDeeNo76]

Maybe of some help?
https://support.microsoft.com/en-us/kb/94651