Audio volume control (increase or decrease) in Java

Question

How do I increase the volume of an outgoing wav audio stream using Java? I'm having issues with various Java TTS engines and the output volume of the synthesized speech. Is there an API call or a doo-hickey.jar I can use to pump up the volume?

Answer 1

If you're using the Java Sound API, you can set the volume with the MASTER_GAIN control.

import javax.sound.sampled.*;

AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(
    new File("some_file.wav"));
Clip clip = AudioSystem.getClip();
clip.open(audioInputStream);
FloatControl gainControl = 
    (FloatControl) clip.getControl(FloatControl.Type.MASTER_GAIN);
gainControl.setValue(-10.0f); // Reduce volume by 10 decibels.
clip.start();