I'm having a problem with my laptop's audio hardware. Most of the time, I choose to play audio through my laptop speakers. But for the first time in a while, I plugged in my headphones. When I tried to play something, no sound came out of them. So while I was troubleshooting the problem, I noticed that every time I plug in the headphones, the mute indicator on my laptop transitions from the unmuted color to the muted color. Ubuntu says that the audio playing on my computer is not muted. But even though Ubuntu continues to say nothing is muted, I can't help but to think that the hardware is not communicating with Ubuntu correctly. My laptop is an HP Pavilion dv4-2160us. Any help would be much appreciated. Thanks in advance!