protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//사운드 설정
mSoundManager = new SoundManager();
mSoundManager = new SoundManager(); 
mSoundManager.initSounds(getBaseContext());
mSoundManager.addSound(1, R.raw.bgm);
mSoundManager.playSound(1);

}


---------------------------------SoundManager.java--------------------------------
import java.util.HashMap;

import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;

public class SoundManager { 

private SoundPool mSoundPool; 
private HashMap mSoundPoolMap; 
private AudioManager mAudioManager; 
private Context mContext; 

public SoundManager() 
{ 
} 
public void initSounds(Context theContext) { 
mContext = theContext; 
mSoundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0); 
mSoundPoolMap = new HashMap(); 
mAudioManager = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE); 
} 
public void addSound(int index,int SoundID) 
{ 
mSoundPoolMap.put(index, mSoundPool.load(mContext, SoundID, 1)); 
} 
public void playSound(int index) { 
int streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play((Integer)mSoundPoolMap.get(index), streamVolume, streamVolume, 1, 0, 1f);
} 
public void playLoopedSound(int index) { 
int streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play((Integer)mSoundPoolMap.get(index), streamVolume, streamVolume, 1, -1, 1f); 
} 
} 

이렇게 작성했는데 배경음이 전혀 안나오는데 왜 안나오는건가요?
이 게시물을