You can adjust the volume on a program like Flash Player by simply increasing the volume of your computer. However, there is another way to further increase Flash Player volume, where you can make a softer move slightly more audible without increasing the power of your computer's speakers.
Right click on the Flash Player's screen.
Scroll down to "Settings."
Click on the icon that looks like a microphone.
Click on the slider and hold it.
Scroll towards the right side to increase the volume.