Pay attention to this or else you won't hear any sound at all:
open the file sound.txt located in the \sound dir and paste these
lines at the end of it:

6750				// Sound ID
0x00,0x01			// Type (0), Flags (0)
67500v8I.WAV			// File name
6000				// Priority
0					// Repeat rate
250,250			// MinVol, MaxVol
0,0			// MinPitch, MaxPitch
0,0			// MinSpeed, MaxSpeed
0x0					// Special FX index
0					// Number of low memory alternatives

save it and that's it. 