Here we will explain Ventrilo normalization, which makes everyones volume the same level from your end. This alleviates the need to adjust people individually, and you will be able to hear everyone talk at the same volume.
Step 1: Click on Setup. Make sure you have Use DirectSound checked twice. Then click on the SFX button in the top right corner.
Step 2: Click on Compressor in the Available column and click Add. Then click on Compressor in the current column and click on properties.
Step 3: Adjust your settings to match the ones shown in the picture. Gain you may adjust for how loud you would like people to sound (higher is louder).
Confirm all open windows with OK. You're now set to go!