My MacBook Pro's right speaker sounds fuzzy
I've had this problem for about a month, not that long after I upgraded my MacBook Pro (2012) to Yosemite. If i remember correctly it just kind of happened suddenly; no forewarning. The right speaker literally sounds like everything that plays through it has been run through the bitcrusher effect on Garageband. It doesn't happen when the computer is plugged into headphones or speakers, so I don't think it's a problem with the sound card. Maybe the speaker is damaged? I also suspected it might be related to how my computer's battery seems to be dying, but that's just a guess, I'm really not an expert.
Thanks in advance for any help you can give me!
MacBook Pro, OS X Yosemite (10.10.3), Owned it for 3+ years.