Webcam Microphone not working

[samsamsam09]

hi, when i record a video in photo booth, you cannot hear anything. Also, when i video chat, the other person cannot hear me at all. When i leave a video on someones facebook wall, you can hear sounds but you cannot make out the words.

Thank you so much!

 

[mynameisraj]

System Preferences > Sound > Input

Is the slider in the middle or towards the right? I know it seems kind of obvious but that's all I got.