Why does milhouse not speak?

[theler2004]

When I play the game and get to the part where I need to send Milhouse and Lisa to the Kwik-E-Mart, Milhouse does not speak, but Lisa does

[wadebear]

Do you mean actual sound or talk bubbles?

If it's actual sound: the actor who does Milhouse is a guest star and not covered by the contract with EA.

If you mean talk bubbles: He should have them.  You may have corrupt game files.