Gakken K. O. Boxing (19xx, LCD, 3 AA Batteries, Model# ?)
Here's an interesting game: You can play it like a normal LCD game, or you can put on the little headset and use your voice to tell the game what kind of punches to go after your opponent with. There's a change... :) Also licensed to CGL (CGL's Voice Command Boxing).
Do I have this? No.