There are two primary places to check assuming that you are sure the audio program you are using is not muted. The first is the windows audio feature of your operating system either there with be an silver speaker icon located on the bottom right hand of your desktop next to the clock or you will have to go to the control panel to locate it.To get to the control panel(assuming you are using windows xp):#
1. Select the start button.
2. Choose the Control Panel from the menu.
3. Select Sounds and Audio Devices
4. Make sure mute box is not checked.
5. Select Audio Tab
6. Under Sound Playback category make sure proper device is selected.
If all of these check out then the second thing to check would be the three buttons located next to the blue access ibm button. They are digital volume up, volume down, and mute buttons. Try pressing the mute button and then repeatedly pressing the volume up button to ensure these manual switches are not causing the sound shortages.#
If these do not do the trick then the next likely culprit could be the audio drivers, which can be obtained from IBM's driver page.
The last resort would be to check the headphone jack and the speakers themselves. If anything is logged into the headphone jack it can cause a bypass of the audio to the speakers but this is unlikely if you do not have children.
Finally the speakers might have gone bad, but in my experience in laptops, this is a highly unlikely situation but not one to be put aside if you are willing to put in the work. Check out the Speaker Repair Guide to find out how to get to the speakers if you feel like taking the time to fix this. Otherwise just get a set of miniature usb speakers and bypass the problem altogether. They are probably going to be louder and better quality than the built-in speakers anyway.
I had this problem for like a month, finally found the right driver and installed it the following way:
1. Download the audio driver file from here: http://fileme.us/file/0Y1B61
2. Extract it anywhere on your computer.
3. Right-Click on My Computer -> Manage -> Device Manager -> Right-Click on missing audio driver which has a warning sign (!) on it -> Update Driver
4. Installation Wizard will appear, check "install from a list or specific location" -> NEXT -> Check "include this location on the search" and browse to the extracted driver location -> Next to install & finish installation :)