exactly that

Daughters toy cat has been through the wash countless times, so I decided to chop it open and remove the sound doohickey that used to purr (but hasn't worked for years) as I was a bit worried about the batteries, unfortunately said daughter has seen the sound thing and disected toy and wants to see if we can get the sound going.

after opening the sound thingie up, found 1 wire missing completely the other has snapped, the batteries corroded and the touch plate worn out, anyway i attempted to reattach wires, new batteries etc but it didn't work( I also soldered my finger which didn't help matters), so anyway, what the hell are these things called i thought I might see if there was one on DX or something, but I just don't know the name of it, so I can't search for it.

Any help would be appreciated

Should say its the size of 4 old 50 cent pieces stacked up