# Configuring Default Volume Parameters

There are lots of different volume parameters that can be set by default in AmplitudeJS. You can initialize the volume to be

# Setting the Starting Volume

You can define the starting volume for when the user initially presses play.
To do this, you need to add a "volume" key to your initialization JSON. This value is any number between 0 and 100. Think of this as a percentage. If you want the volume percentage at 35%, set this value equal to 35.

	Amplitude.init({
		"songs": [...],
		"volume": 35
	});

# Setting the Volume Increment and Decrement Values

AmplitudeJS allows you to have volume increment and decrement buttons. Each time one of the buttons is pressed, the volume increments or decrements a certain amount. You can configure AmplitudeJS to have values set for how much the volume should increment or decrement when you initialize.

  Amplitude.init({
    "songs": [...],
    "volume_increment": 10,
    "volume_decrement": 10
  });

Think of these values as a percentage of the volume that AmplitudeJS adjusts. So every time we increment AmplitudeJS the volume now goes up by 10% or down by 10%. The default for this is 5%.