public void setPitch(float pitch) {
        if (pitch < 0.5f || pitch > 2.0f) {
            throw new IllegalArgumentException("Pitch must be between 0.5 and 2.0");
        }

        this.pitch = pitch;
        if (channel >= 0)
            getRenderer().updateSourceParam(this, AudioParam.Pitch);
    }
Set the pitch of the audio, also the speed of playback.
The value must be between 0.5 and 2.0.

@param pitch The pitch to set.
@throws IllegalArgumentException If pitch is not between 0.5 and 2.0.
jme3-core/src/main/java/com/jme3/audio/AudioNode.java