The same sound when I get notifications

Hi.

After I downloaded iOs 10, it has been some difficult things that happened to my iPhone 6 that I can´t handle. The battery is going way to fast, but the thing that I´m most angry about, is that I get the same notification-sound on every notification I get. That means I get the same sound when someone send me a snap, or texts me on messenger. Snapchat has it´s own sound, and so does messenger, but my phone suddenly use the one and only sound on every notification. I have turned off and on my phone, nothing helps. It aint possible to change which sound you would like to have on Snapchat, it´s only one sound. But I get a weird sound on everything and it´s annoying me.

Can someone please help me?