Ipod touch 2 gen Sound and Freezing problems

My ipod touch has been emiting a screeching sound for about a month now every time I play music o unlock or watch a video instead of the normal sound that shoul come out on both headphones and speakers. Aside from that it freezes when I try to watch a youtube video or start an app and the only way to make it work again is resetting it.

I have tried:

-Reset all settings
-Erase all content and Settings
-Full restore on itunes to both factory settings and a one year old back-up.
-DFU mode and new firmware 4.2.1


Any tips?

 

thanks to both of you. Well I guess 5 years was a good lifetime for this kind of device

 

Yep, you're right 4. Then it should have lasted another year