MainActivity.java

public class MainActivity extends Activity {

	ImageView maru_button,batsu_button,qbutton,rbutton;
	private SoundPool mSoundPool;
	private int maru_SoundId,batsu_SoundId,q_SoundId,r_SoundId;

	InterstitialAd mInterstitialAd;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		maru_button = (ImageView) findViewById(R.id.maru);
		batsu_button = (ImageView) findViewById(R.id.batsu);
		qbutton = (ImageView) findViewById(R.id.qbutton);
		rbutton = (ImageView) findViewById(R.id.rbutton);

		maru_button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				//音声
				if (mInterstitialAd.isLoaded()) {
					mInterstitialAd.show();
				} else {
					mSoundPool.play(maru_SoundId, 1.0F, 1.0F, 0, 0, 1.0F);
				}
			}
		});

		batsu_button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				mSoundPool.play(batsu_SoundId, 1.0F, 1.0F, 0, 0, 1.0F);
			}
		});
		
		qbutton.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				mSoundPool.play(q_SoundId, 1.0F, 1.0F, 0, 0, 1.0F);
			}
		});
		
		rbutton.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				mSoundPool.play(r_SoundId, 1.0F, 1.0F, 0, 0, 1.0F);
			}
		});

		AdView mAdView = (AdView) findViewById(R.id.adView);
		AdRequest adRequest = new AdRequest.Builder().build();
		mAdView.loadAd(adRequest);

		mInterstitialAd = new InterstitialAd(this);
		mInterstitialAd.setAdUnitId("ca-app-pub-3940256099942544/1033173712");

		mInterstitialAd.setAdListener(new AdListener() {
			@Override
			public void onAdClosed() {
				requestNewInterstitial();
			}
		});

		requestNewInterstitial();

	}


	private void requestNewInterstitial() {
		AdRequest adRequest = new AdRequest.Builder()
				.addTestDevice("SEE_YOUR_LOGCAT_TO_GET_YOUR_DEVICE_ID")
				.build();

		mInterstitialAd.loadAd(adRequest);
	}

	@Override
	protected void onResume() {
		super.onResume();
		//音声
		mSoundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
		maru_SoundId = mSoundPool.load(getApplicationContext(), R.raw.correct, 0);
		batsu_SoundId = mSoundPool.load(getApplicationContext(),R.raw.wrong,0);
		q_SoundId = mSoundPool.load(getApplicationContext(),R.raw.question,0);
		r_SoundId = mSoundPool.load(getApplicationContext(),R.raw.result,0);
	}

	@Override
	protected void onPause() {
		super.onPause();
		// リリース
		mSoundPool.release();
	}
}