Alternative to iPod

I still use an iPod Touch although I also have an iPhone. The iPod is a backup device kept on my nightstand, used mainly to play recordings that help me fall asleep and occasionally used to check weather, send a note, etc. The phone is, of course, used much more often. I suspect the iPod's days are numbered and wondered how I could get an alternative. Could I get a new phone and then disable the phone function on my current one? It's about four years old, but I'm perfectly satisfied with it; although I haven't been planning to upgrade, I would if it makes sense. Would I still be able to do everything else on this phone as long as I have a WiFi connection? Or is there a device made by some other company that I could use, for example a less expensive phone that, again, wouldn't be used to make calls, or a device to which I could download my recordings (currently in the Music app, although I might be able to find new ones online) that isn't a phone? I really want a second device of some sort.