wire connectors or similar wire shrinky covers
scrap speakers harvested from something good that broke
a Mic I used one from a internal Mic from laptop
some misc. Foam from scraps of electronic shipment packaging
Alternate materials is buying a Mic and buying a speaker at your typical retail chains: Radio shack, or online at mouser, adafruit or the maker shed, they are cheap and are definitely better then what is currently in the device, just on age alone.