Easily doable. (outside of the mechanical mouth movements!)
Actually.. this can all be done VERY (very) cheap.. but it all depends on how far/how much you guys wanna do.
In theory.. you could get a $2.00 sound board off eBay...
coupled with a speaker and some batteries...
all you need if a few 'switches' to trigger the audio clip playback.
However if you want to go a little bit further.. and not be limited to amount of I/O pins for audio playback...
you could couple this with an Arduino... (Pro-Mini costs roughly another $2.00 USD off ebay as well)
Then you could code it to do whatever.. and trigger playback based of whatever you want. (adding PIR sensors...etc)
If you wanted to go even further.. you could a bluetooth module to the audio board and Arduino set-up..
So you could write an app (MIT App Inventor 2 for Android based phones)... that triggers the audio playback whenever a specific button is pressed.
So outside of time/learning... the most advanced set-up (that was posted) will only cost (roughly) under $20.00 Maybe just $6-8.00 if you have battery/speaker stuff..etc
I could do this... (but I dont have a Chucky prop).... but I'd be willing to help others learn if they want.
You'd need to some audio files of the audio playback you want to trigger to start with.
Maybe start throwing a feature list together?
'shock/vibration' sensor triggered?
'distance/proximity' sensor triggered?
Full blown bluetooth and phone app controlled?
For the first two...
would it be a random playback from all audio clips on the microSD card?