Need to stop the remote push notification sound when a new push notification arrives.

I have fire alarm application. During app is terminated state, a remote push notification with a custom sound is receieved, the app will play the sound. After some time the alarm clearing notification received. I need to stop the custom sound during the second ntoification. Also if the second notification didn't arrive, i need to repeat the sound. The audio which i saved in bundle has 22 sec length.

Please respond if anyone have this issue?