Main Menu - Control Panel
The slider on the right will adjust the level of MIDI Musical Instrument Device Interface - A system that allows electronic musical devices to communicate. Numbers describing pitch, volume, on or off, etc. can be sent between devices. volume that MusicGoals sends to the Midi output device. This will affect the loudness of the music examples that are played during the drills. It will not affect the volume of the reward sounds after each drill.
You may turn the reward sounds on or off with Main Menu - Control Panel - Midi and Sound.
To adjust the volume of the reward sounds adjust your speakers or use the Windows Volume Control and adjust the wave volume: Start - Programs - Accessories - Entertainment - Volume Control.
see also: Midi and Sound Setup, Sound and Midi, Control Panel