When troubleshooting sound problems on Macs, you can find thefix quickly if you isolate the possible problems first. Regardless of youroperating system, it will make things easier if you can narrow down thepossible points of failure by momentarily unplugging any sound devices.Following simple change of sound settings and testing internal sound alerts canfix the problem.Instructions
Launch iTunes or another media player applicationand have it play continuously to start troubleshooting. Make sure the volume isnot muted or disabled. Move the volume slider on the menu bar up and down. Youcan also use the keyboard's Increase and Decrease volume buttons (usually F4 todecrease and F5 to increase the volume).
Unplug any headphones that might be connected toyour computer's headphones port. If your computer
has internal speakers,unplug any external speaker plugged to the audio port to isolate the problem.Check if sound is working properly through the internal speakers.
Go to System Preferences on your Mac menu. Clickon the ''Sound'' icon, under the Hardware section. The Sound settings pagedisplays three main buttons: ''Sound Effects," ''Output" and''Input." Click on the ''Output'' tab. Select the ''Internal Speakers,Built-in Output'' option, and raise the ''Output Volume'' at the bottom of thatwindow. Check if sound is working properly.
Go to the ''Sound Effects'' tab, and make sure the''Alert'' and ''Output'' volumes are up and not muted. Select ''InternalSpeakers'' from the ''Play alerts and sound effects through'' drop-down menu.Click on any of the Alert Sounds in the left column and test to see if theysound as you change from one to the other. Check if sound is working properly.2.
Launch GarageBand. A default piano track willappear. If it doesn't appear, click on the ''Track'' Menu and select ''NewTrack''. Choose a Software Instrument from the dialog box, and then choose aPiano from the selection of Instruments.
Click on "Menu." Select ''Preferences''and click on the Audio/MIDI tab. For Audio Output, and Input select thecorresponding ''Built-In Output'' and ''Built-In Input'' from the drop-downmenus. Confirm the action.
Click on the Piano track. Under the ''Windows''menu bar, select the ''Keyboard'' option, or press [ Command + K ]. A keyboarddisplays. Click on any of the keyboard keys. You should hear sound coming outof your internal speakers.
Make sure there is no headphone jack inserted in the computer. If sound doesnot work, try quitting the application and launching it again.
If any of the previous steps do not fix the soundproblem, reboot and try again.
If you see a Disabled Volume alert when you try to raise the volume, alsoreboot. This is a known bug in Macs