Sound byte machine

Hi there newbie to arduino. Have some basic electronics knowledge form years ago. I have a nice old panel from a video recording controller. Has about 20 buttons on it. I want to use it to connect to mp3 player (via arduino )module to play specific sound byte that I have recorded. I will have to understand how each button is identified from the panel. Can anyone give me some basic tips? I assume the button press will produce some serial signal which I will have to decipher. Thanks

How do you power the controller? How many lines come out of it?

Try to find out more about the output of the controller (voltage levels, frequencies...). A scope will be very helpful for that task. If in doubt, provide some curves of signals from different buttons.

It may be easier to remove most of the controller hardware, and connect the buttons directly to an Arduino. Then you can be sure which button shorts which lines (maybe a matrix), and the freed space in the controller case (if any) may be sufficient to host an Pro Mini.

For $50 you can get an MP3 Trigger that will connect to 18 buttons and have each one play an MP3 file on a Micro-SD card. https://www.sparkfun.com/products/11029