Sound/Audio crackles and gets stuck with lot of disturbance often

Hello. I have a dell Inspiron N5110 and I had a similar problem occur over a year ago where the audio would crackle and stop and it would freeze in the middle of playing and the screen would get stuck. I have not had that problem since last year when it went away on its own.  However, since last week, I have been having similar issues where the audio is working fine one moment and on a different account on the laptop, but on the main account it freezes and crackles and there is disturbance. I have restarted my laptop 3 times and the 3rd time it went away for the most part but then it came back. I have used compressed air to try to clean out my air vents, but I am not sure how successful it was because I did not see much or any dust come out.  My last system update was two weeks ago. How can I fix this? Thank you.