LibGDX загрузка аудио

Sound dropSound;
Music rainMusic;
// загрузка звукового эффекта падающей капли и фоновой "музыки" дождя
dropSound = Gdx.audio.newSound(Gdx.files.internal("drop.wav"));
rainMusic = Gdx.audio.newMusic(Gdx.files.internal("rain.mp3"));

E/AndroidRuntime(7018): FATAL EXCEPTION: GLThread
E/AndroidRuntime(7018): com.badlogic.gdx.utils.GdxRuntimeException: Error loading audio file: drop.wav
E/AndroidRuntime(7018): Note: Internal audio files must be placed in the assets directory.

dropSound = Gdx.audio.newSound(Gdx.files.internal("drop.mp3"));
rainMusic = Gdx.audio.newMusic(Gdx.files.internal("rain.wav"));

 while(iter.hasNext()) {
            Rectangle raindrop = iter.next();
            raindrop.y -= 200 * Gdx.graphics.getDeltaTime();
            if(raindrop.y + 64 < 0) iter.remove();
            if(raindrop.overlaps(bucket)) {
                  dropSound.play();
                iter.remove();
            }
        }

SoundPool sounds2 = new SoundPool(5, AudioManager.STREAM_MUSIC,0);// 5 звуков