This code will only work if you have Gameshark and you have the code that almost any door is open.
In the area where Jill is injured and you are playing as Carlos, after you beat Nemisis and you have just left the Clock tower, skip the hospital and go strait through the park.
As you may notice you are Carlos instead of Jill. Continue forward and you will run into Carlos in the Sewage plantWhen you meet Carlos you are Carlos, but with Jills voice.
I do not know how it will affect the rest of the game so don't save it with Carlos instead of Jill unless you might want to risk messing up the game.
Added by: Lee and Fred , ID#6404