Sound Output Problem

[Kashchei]

I woke up this morning and tried to watch a linked video on a webpage. I saw the video, but there was no sound (this had not been a problem the evening before). I am using USB soundsticks, so I checked to make sure that they were plugged in, and they were. I opened iTunes and sound came through the Soundsticks; I switched to the internal speaker and it worked there as well. When I tried the same with another embedded video, however, I only got sound from the internal speaker.

Has anyone had a similar problem or does anyone know how to fix this?

P.S. I have deleted the file com.apple.soundpref.plist and restarted, but this did nothing.

 

[BlueRevolution]

Is the sound on the video player turned on? Most Flash-based video players like YouTube's have their own volume control/mute tools beside the scrubber.

 

[Kashchei]

Is the sound on the video player turned on? Most Flash-based video players like YouTube's have their own volume control/mute tools beside the scrubber.

Yes, the sound is on and the volume turned up on both the video player and the computer.

Sorry, I should have mentioned that in my original post. I should have also added that I get the same problem no matter which browser I use and no matter which webpage I try to watch video on (YouTube, the new Apple ads, etc.)