dB question

Is there any way for me knowing how loud is 55 dB for example? (the number is just an example, I want to know if there is a way converting those dB numbers to actual sound).

Yeah, that's a good site. Though, decibels don't tell the whole story. You also need the quality factor. Lots of computer speakers can hit 100+ dB, but above 75 they just distort so badly you can't hear what the sound is supposed to be anyway. When getting into high numbers, you need the quality there to back them up. That's why my 93dB home theatre sounds better than the 114dB coming from my friend's Z-680's.

Also, don't be drawn in by high wattages. They mean absolutely nothing, unless backed by efficiency and quality.

XP 2500+ Barton
A7N8X Dlx
2x512MB Corsair PC3200
MSI GF3 Ti500 w/64MB DDR
16x DVD-ROM
2x80GB 7200RPM Maxtor
Onboard audio

My computer is bigger than your computer....