java - Waiting specific time to increase sound libgdx

I want to wait a moment (.5 seconds) before I increase the sound, how can i achieve this without using Thread.sleep, because i want my game to keep runnig.

Answer

You can either use a java timer approach: http://developer.android.com/reference/java/util/Timer.html

Or you could simply keep track of the time elapsed since the increase volume action began. Maybe something like this in your render method or somewhere else:

float elapsedTime;
long actionBeginTime;
boolean volumeIncreasing=false;
public void render () {
    if(volumeIncreasing){
        elapsedTime=(System.nanoTime()-actionBeginTime)/1000000000.0f;
        if(elapsedTime>0.5f){

            increaseVolume(); //your method that increases volume
            volumeIncreasing=false; //can be set here or in increaseVolume()
        }
    }
}

Of course you need to set volumeIncreasing to true and actionBeginTime=System.nanoTime() somewhere when the action begins.