So you want to go beyond the simple beeper sound in your Arduino and want play audio, either music, voice or any other audio.
You have a few options to do so. Here’s a few:
Arduino Audio No shield option
You do have the option to get audio out of Arduino with no shields at all! It does take some breadboarding, but it can be done. All you need is hookup a microSD card and the D9 output.
Check out his excellent tutorial on how to have Arduino Audio with no Shield.
My opinion: It’s very tricky to get the microSDcard working as shown in the tutorial above. You should consider getting a microSD card slot.
The library at the website above it just awesome. I use it on the MICO Shield for Arduino (see below)
Audio conversion: with this library you have to convert MP3 or WAV files into a RAW format. The library author does provide instructions on that. I however came up with alternate method using Audacity (link)
Arduino Audio Shield Option
A much more convenient option to add sound to your Arduino is to use an Audio shield. Audio shield come in different flavors.
One popular shield for adding audio is Adafruit Wave Shield
Another option for Arduino playing audio is to use the MICO Shield. MICO has the circuit that you see in the tutorial above, no need for you to do the breadboarding. Just like in the that circuit you do need to convert the MP3 / WAV file into a raw format for playback. (How-to Convert audio)
Now here’s the cool thing about MICO: in addition to playing back audio, MICO has another audio port that can be plugged into a cell phone’s audio jack. This let you create Arduino projects that can receive and place phone calls. Learn more about MICO at HelloMICO.com
There’s plenty of options out there to add audio to your Arduino. You can go barebones and build a breadboard from scretch; or you can get a shield that makes your life easier. MICO shield is an option that offer Arduino audio and more, so it is a good option for audio projects!