This ISD1820 Voice Recording Module is a very interesting stuff. You don't need to prepare a speaker and a mic - both are included in this module! After connecting to the power, you can press REC to record a 10 second voice. Press PLAYE to play the complete voice once. Press and hold PLAYL it will play the voice and it stop when the button is released. It can also be controlled by Arduino - that means you can make it rings when someone stands in front of the door, for instance. You can definitely think of other interesting projects with your creativity!

ISD1820 Voice Recording Module