Need constant message notification sound

[megaalert]

I just upgraded from a Samsung Note 2 to Note 3 and use Aqua Mail for business emails.
When I am "on call" for work, I set the notification sound to "hangout" which would constantly make a noise until I read the inbox.
Unfortunately, on the Note 3 that sound is no longer available.
Is there a way to download a custom notification sound?

[Kostya Vasilyev]

The sound picker is a standard system component, and the sounds vary with the device and Android version.

I suggest installing one of the apps that let you pick sound files -- one such app is called Rings Extended (from an Android developer), free in Play. Some file managers also do this (ES Explorer, Solid Explorer). You'd see those apps listed when you tap to choose a sound.

Then it's just a matter of getting a looping notification sound somewhere, to put on the device's memory card.