This is ideal. It's called the MP3 trigger. You connect buttons, switches or whatever to its 18 inputs and depending on which input you trigger, it will play a corresponding audio file from a micro SD card:
https://www.sparkfun.com/products/11029It's pretty much made for this same application, it's very easy to use and comes with almost everything you need. It's US $50 though.
If this is a one-of project, that shouldn't be a problem. As a whovian, I'd like to see the finished Doctor Who game
Make some noise with your next project! The MP3 Trigger board is built to make it MP3 sound integration easier than ever. The board has 18 external trigger pins that will directly trigger pre-selected MP3 tracks, and a full-duplex serial control port that provides full transport control, remote triggering for up to 256 tracks, and fast real-time volume control. MP3s are stored on FAT16 formatted SDSC or FAT32 formatted SDHC micro-SD flash memory cards. In addition, optimized code now achieves 192Kbps stereo playback from a wider range of cards than before.
Check this part, this way you can integrate it to your score display board:
There is also a “Quiet Mode” feature that can be enabled via the serial control port. In this mode, the trigger inputs don’t start tracks directly, but instead produce a serial message indicating which triggers were activated. A host microcontroller can thus monitor the trigger inputs and then start any track or sequence of tracks via the serial control port, making the triggers much more flexible.
No, I don't work for Sparkfun
As for the game, you absolutely need dual hearts, a sonic screwdriver, a weeping angel maybe...
I should catch up with the series. I left just before the anniversary special.