Wave Shield voice changer with audio output delay

Other Hardware Audio
1

Hello, I would like to ask how could I add an audio output delay (e.g. 3s) to my Adafruit wave shield voice changer please?
From the tutorial here, it seems like I will need to add the delay at the circular buffer. I am new to wave shield and Arduino, may I ask if that is the right way? If so, where and how shall I do it please?

Cheers,
Karen

PS Voice changer code here

2

You need to add extra memory to act as a buffer, there is no where near enough on the Arduino itself.

I have used a 23K256 chip attached to the SPI bus.
You can use the D/A on the wave shield chip but you will need an amplifier to get the audio signal big enough for the internal A/D.

Not exactly a beginners project.