Why are my ears ringing?

I don't listen to much music, and when I do its at low volume and usually soft classical type music. I listen to it primarily at night, but only for like 10 minutes. I'm 14, and yesterday I woke up with my left ear not hearing as well as usual. I can still hear out of it, but its abnormally impaired. Today, I realized that there's this faint ringing sound, and it feels like something is blocking my ear. I told my parents, but they said they won't take me to a doctor unless it lasts for a long time. The other ear is totally fine. When I asked friends if they've had similar experiences, most of them said they had and that it goes away after a while. Is something wrong with my ear?