The only thing I can think of is Alphie the robot. I played with that toy for years. However, Alphie came with cards that you would put in his chest, not tapes. If it isn't Alphie, it's probably something very similar.
Picture of Alphie the Robot:
http://www.doyouremember.co.uk/images/memorabilia/Toys/alphie.jpg
http://www.pickletreats.com/2XL/
http://homepages.compuserve.de/JCBaumeister/MB_2XL_Robot.JPG
We used to have the 8-track version. When I was a little older I saw a tape cassette version, but it didn't look as cool.