Another fun fact: Phil Collins not only sang the songs for the English version. He also did it for other 4 languages: Spanish (both Spain and Latin America, being the only Disney movie in which the songs of both versions sound the same), French, German and Italian, so people from those countries also had an unconventional Hey, It's That Voice! moment.
In the Mexican Spanish dub, Adult Tarzan was voiced by the late soap opera and movie actor, Eduardo Palomo, who was casted as Tarzan because Palomo looked helluvah lot like Tarzan. In fact, one of his most famous roles in a soap opera looked like as the Disney's rendition of Tarzan, years before the movie was ever conceived.
In the Spaniard dub:
Kerchak is voiced by Pablo Adán, who international audiences know as Fauno's voice. However, Spanish kids recognized him at the time as Goliath's Spaniard voice.
Tarzan was voiced by Jose Luis Gil, who among many others, already played Buzz Lightyear and a couple of years later became famous in Spain as a Live-Action TV actor in Aquí no hay quien viva, a popular Spanish Sitcom.
Throw It In: The scene where Jane was ranting about what happened to her, her father and Clayton, after being rescued from the baboons? That whole thing was improvised by her voice actor, Minnie Driver.
Likewise much of Professor Porter's reaction to her ranting was improvised along with other lines such as "Oh, just like Aunt Isabelle" when Jane describes how Tarzan walks.