Being unable to hear sound when playing music on your computer can be caused by several factors. These factors may depend on what external devices you are using to amplify sound, what kind of computer you have and what application you are using to play music.
Make sure the volume is turned up both on your computer and in the program you are using to play music. Turn up your computer's volume either with the volume keys on the keyboard or by clicking on it from within the desktop. Look for the volume icon or slider bar. In PCs, the volume can also be found in the Control Panel and, in Macs, the volume can be found in system preferences. Make sure that mute is not on. Digital music players and applications such as iTunes or online radio stations such as Pandora usually have their own separate volume controls. Look for the volume icon and make sure it is also turned up.
If you are using external speakers plugged into a computer or laptop, they will also generally have their own volume control. Check to ensure that the speaker volume is turned up. Also, if you are using external speakers, double check that the speakers are plugged into the appropriate sound jack on the computer. Some external speakers have a separate power cord. Make sure that it is plugged in. If your speakers are USB (Universal Serial Bus), plug them into the appropriate USB jack on your computer. Also try unplugging the speakers, restarting your computer and plugging them back in.
If your computer is a PC, you will need to check that your computer has a sound card. In your Control Panel, click on "System and Maintenance," "Device Manager," then "Sound," "Video and Game Controllers." If there is not a sound card listed, consult Windows IT Resources for ways that one can be installed. The driver for the sound card may also need to be updated, especially if you are installing a new sound card. Go to the Sound, Video and Game Controllers window, and then click on "Update Driver."
If your computer is a Mac and you are trying to listen to music with your computer's built in speakers, go to "Sound," click on "Output" and double check that Built-In Audio is selected. If you are using a digital receiver such as a satellite receiver, then Digital Output should be selected. If you are using external speakers, open your Applications folder, then the Utilities Folder. Your speakers should be listed in the System Profiler. If not, they may be incompatible with your operating system.
Other Possible Issues
If your computer is connected to a digital receiver such as a satellite radio receiver, ensure that the receiver is set up for input. Consult the information that came with your receiver for set up assistance. If you are listening to a music file or a CD, try a different one. The file you are trying to play may be corrupt or the CD may be scratched. If you are using external speakers or headphones, there could also be some debris lodged in the jack. Use a toothpick to gently feel around and clear out any debris that may be keeping the plug from properly connecting in the port. If everything seems OK with your computer, there may be issues with the external device. Consult the manuals for these devices for technical support.