The Larson Scanner (moving LED array) with its AA battery pack is at top. It is a kit from Evil Mad Scientist. The board in the center, (underneath) is an Arduino Uno. On top of that is an Adafruit Wave Shield. It's a kit and yes I didn't get it right when complete, I had a cold solder pad on the SD card interface. This plays the cylon sounds - this consists of the moving eye sound and then 6 phrases that can be triggered from an IR remote (not shown, any remote will do, more below). The IR signals are captured by a Radio Shack IR receiver (black, between the two blue boards).
The unit is powered from a 9 volt battery connected to the Uno. The audio out on the Wave Shield was amplified as the volume produced by the shield was not very loud. I happened to have a vintage Radio Shack mono amplifier. The Uno+Shield+Battery were housed inside the pumpkin in the plastic case at left (from Michaels, use your 40% off coupon).
Wiring: The Wave Shield connections are as recommended by Adafruit (using Digital pins 2, 3, 4, 5, and 10). The IR sensor was coded to use Digital Pin 9 (along with +5 volts and ground). The astute will notive I did not take the ausio from the 1/4" jack (not enough room in the plastic box) - I soldered two 90 degree header pins on the board's audio out and connected the yellow and orange cable to a 1/4" plug.
Code: The code is at https://github.com/TheKitty/CylonPumpkin. You should get the WaveHC and WaveUtil libraries from adafruit.com. IRremote library by Ken Shirriff at http://arcfn.com. You should use one of the IRtest programs with Ken's library to discover the codes for whatever remote you chose. I used an old Creative RM-1500 remote but you can use any remote and map the codes you discover to the keys you push. This project used number keys 1 to 6 for effects, mute to turn off sound, Volume + to turn it on. The code is not overly clean as there was a bug with the mute button so I ignored presses that turned out to be just over 1.5 seconds. It was frustrating - you'll probably have better luck. The sounds can be found via Google "Cylon WAV". I cannot post the sounds as they may be copyrighted.
Other than the mute issue, it was a straightforward and fun build. I'll look to reuse the Uno and Wave Shield to try out the Adafruit Voice Changer.