Macbook pro acting up... keeps adjusting sound volume by itself

do you guys have any problems with this? for some reason, sometimes it will automatically turn up the volume by itself and it'd loop that stupid clicking sound even when its at 100% volume... it does it randomly when im using the macbookpro

I have noticed this on my MBP. The most annoying thing it does is turn the sound on when i have muted it. You sitting in the lounge with company doing some quiet work, open up OSX version of Messenger and the sound automatically turns on making its Messenger beeps! I didn't turn it on, you have to press mute again. The funny thing is according to the icon in the top bar mute is on, so why am i hearing sound?