how to find out which app is making a specific notification sound

[D Swapp]

I my samsung galaxy s4 I kept hearing a camera shutter sound about every couple of minutes and that worried me because I was afraid that through one of my apps someone was able to screenshot everything on my phone. I did something, I'm not sure what but now instead of the shutter sound it whistles at me. I've gone through every app I could think of that might be making the sound and I checked my settings and I haven't been able to find anything and I haven't been able to make it stop I still don't know which app is doing this or causing it or if it is something to do with the settings on the phone. It's very annoying to have your phone whistling at you every couple of minutes and not know why. Whichever it is I would love to be able to find out which one it is and turn it off. If anyone knows how I can do this or if there is a specific app that I can download that would help I would really appreciate knowing. Because before I have to do a factory reset. Because factory resets really are a pain in the neck. If anyone has any idea on how to fix this problem please please let me know. And please for sure answer in the simplest terms. I thank you in advance for your help.
Danielle

 

[vinnie_boombhats]

Have you tried settings>apps>running and forcing stopping anything that seems unnecessary? Or even just restarting the phone?

 

[extraclass]

Hold down the HOME key and a screen will tell you everything that is running on your phone! At the bottom right tap on the CLOSE ALL Button. When you hear this sound hold down the HOME button again and see what is running on your phone. Also, drag the home screen down from the top and you should see all notifications with a time. This should tell you what is causing the sound. Let us know what you found out!