Loud speaker has stopped working. Is this the correct part?

The Loud Speaker on my iPhone 3G has ceased working. The phone is over a year old and I didn't buy extra cover so I am going to repair it my self. I was looking at the parts and I think this is the correct part I need. Dock Connector Is this the correct part?

Just some extra information, the sound I noticed was working fine in the arvo but that night I noticed it stopped working. I have restarted it multiple times can't get a peep out of it.

Been about a week since it has stopped working.

The phone is jailbroken but as been on this os for awhile now so I don't think it's software but I am going to try restoring before I crack it open.

As far as I can tell everything else is working fine.

I have tried the trick of putting in and taking out the headphones and I have also tried cleaning the port.

The os is 3.1

Thank you