How Loud?, Measuring Loudness (Decibels) Options

[korektphool]

HI ALL!
This is what I want to do:
I have a sample (AIFF, mp3, whatever). I want to measure how loud the sound is, in decibels. Is there an application that can do this? Or is there a VST instrument that can do this once I load the sample in Cubase?
All help is appreciated.
PS In case you are wondering why I would want to do this, it is for a science project (I go to school).
Raghav Kaushik [KorektPhool]

[Jeff Pelletier]

Alright....Here's something that screws everyone up!
The dB...
The dB is simply a way of descriding the ratio between two quantities! It is not a unit of measure in and of itself.
However, if you attribute a reference to the dB it becomes useful.

Ex. dBm-ratio between 2 electrical POWERS
dBV-between 2 voltages
dBSPL-between sound pressure levels

If you are trying to find out how "hot" a signal is recorded on a medium, play it back on whatever DAW you have and meter dBm. Now, if your meters have the ballistics and scale of typical VU meters, 0VU=+4dBu(pro standard gear) or -10dBm(consumer standard).

If Your meters are on a dBfs scale (usually the case on digital gear), 0VU=anywhere from -20dBfs to -8dBfs.(There is no standard...it depends on the gear manufacturer).

As for metering the human perception of the loudness of that sample in dBSPL....that depends on about a million things...like....how loud is the volume turned up on your monitors!

Hoped this helped...maybe i didn't even come close to answering...but i hope you learned something (seeing as you're in school and all)

-Good luck!