Sound.Volume

From Xojo Documentation

Property (As Integer )
aSound.Volume = newIntegerValue
or
IntegerValue = aSound.Volume

Supported for all project types and targets.

Controls the volume of the sound.

Notes

The range is from 0 to 100; 0 mutes the sound and 100 plays the sound at the "normal" volume set in the computer's volume setting. Default is 100.