[dpeterson]

For a stand-alone, triggerable audio source, check out Adafruit's Audio FX boards. Ranging in price from $15 for the 2MB line out version, to the $30 16MB, 2x2W stereo class D amplified version, they're purpose-built for props, costumes, toys and other small portable projects. These boards have 11 inputs for triggering playback of stereo WAV/OGG files in various ways, ranging from basic triggering to looping, sequential and random modes. Just attach to a PC, copy your audio files onto it, detach and it's ready to go. Required power is 3-5VDC so think wall wart, 3xAAA battery pack or use an Adafruit LiPoly battery (from $5). They say there's a serial protocol for finer control if you want to connect it to a separate microcontroller. Playback quality is high quality stereo.

I noticed their website a little while ago and have found a lot of hardware there that lends itself to DIY Halloween projects.

https://www.adafruit.com/

 

[EyeballsStudio]

That's exactly what I was looking for! I want to build a prop chainsaw for a Leatherface costume. At first, I wanted to use an Arduino with an MP3 shield and a separate amplifier, but this is much better.

 

[dpeterson]

They have the Arduino shield stuff as well. Just depends on one's specific requirements. I've been exploring their RGB LED lighting stuff for use with various costumes and props. One can find stuff a bit cheaper buying from China, but these guys (more specifically, Lady Ada) have their act together, creating useful and unique stuff.