My ipod 5 battery and sounds.

My ipod touch 5th generation keeps ringing at random times when it is charging. i usually am the person who knows all about these things, but i just cant seem to figure it out and i hope that you can help. Heres my issue.

So, when i charge it, it does charge. Its all the way plugged in. Ive checked that trust me. It does have ios 7 and i havent dropped it or ANYTHING. WHen the battery is either low or high or in the middle it rings. (the sound of it when you start charging it) it could do this for ever. but i stop it by just turning it off and unplugging it. so anyways, it does this often and its so very annoying, its not because my ipod may be overheating because it never is. Please help. i have tried to look this up and i dont think this is normal. Thanks....Morgan H.

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