public void setVolume(float volume) {
        if (volume < 0f) {
            throw new IllegalArgumentException("Volume cannot be negative");
        }

        this.volume = volume;
        if (channel >= 0)
            getRenderer().updateSourceParam(this, AudioParam.Volume);
    }
Set the volume of this audio node.

The volume is specified as gain. 1.0 is the default.

@param volume The volume to set.
@throws IllegalArgumentException If volume is negative
jme3-core/src/main/java/com/jme3/audio/AudioNode.java