https://youtu.be/w9fIe_2RRgg
Audio download (6MB mp3):
https://1drv.ms/u/s!Ag0GQL2cf965jeVaMy-LEfPsTUH53Q
It's the Adman Electronics speech synth cartridge, based on the GI SP0256-AL2 chip:



Also, I got the manual from here:
https://archive.org/details/VIC-20_Spee ... 1982_Adman
Finally, I plan to do a ROM dump of this cartridge as well, but it will be several months before I get the chance to try it.