Is it just me or are there new ad's everywhere?

[Katie]

OK so for three days now I thought my computer had a virus cause I was hearing audio ad's almost nonstop The ad's would even overlap each other and it would sound like 5 voices at once coming threw my speakers. Now I ran some scans and deleted some suspicious files but the ad's kept coming. Now I do leave multiple tabs open and I have started catching the commercials that the audio is playing on yahoo (mainly) facebook and youtube. I can also click the sound off feature for most of these ad's and that stops the audio. Or I if I keep these websites off my computer there are no ad's....But I have never had ad's just randomly play on these websites before and I wanna leave multiple tabs up while still playing music...Is this happening to anyone else or is there something actually wrong with my system?