Adafruit Wave Shield
Customers who bought this product also bought:
This developed by Adafruit shield allows you to add audio on an arduino with a DAC or NAC (Anloga digital converter).
It has a floor of filter and a pre-amp for a quality audio output.
It is also possible to directly read WAV files on a SD card inserted into the shield SD/MMC card reader (file WAV 22 kHz mono 16 bit uncompressed).
The shield is sold in kit with all necessary components to its mounting soldering yourself.
Documentation of the Adafruit Wave Shield: http://www.ladyada.NET/make/waveshield/