I thought of this whilst doing a reality check by checking to see if anything weird was going on around me and I heard music and I remembered "Oh ya, it's coming from the computer." Also in my dreams, I hear sounds from the outside world coming into my dream. I thought about how in MANY of my dreams I hear music or noise coming from nowhere and so I realized I should start checking to see if I'm dreaming by checking to see if any sound has a rational source.

I don't know if this will work for everyone but 80% of my life is spent listening to music. Hopefully this will induce some LDs!