Left eardrum crackling when I hold my nose and blow out?

When I close the nostrils of my nose with my fingers and blow out and in and out I can hear my left eardrum crackle in unison. There's no pain. When I push under my ear it crackles too. Is it earwax? If it is how do I get it out? I use Q-tips for my ears should I stop? What else could be causing this?