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]

[korektphool]

Plz help, cuz i rwally need 2 start thi assignment soon.
korektphool
thx in advance

[sethjacquay]

korektphool,

I don't know of any application that calculates the average decibel
rate of a song. There is probably a DAW that does it.

I would just dump the track into Soundtrack or another DAW
and watch what it peaks at and what its softest level is.

Also, isn't the decibel range dependant on the recordings wordlength? (i.e. 16 bit or 24 bit)

At anyrate, maybe you should write the program that does this.

Here is a hardware device that measures levels:
http://www.tnt-audio.com/clinica/spl-meter_e.html

and here a link to some documents on loudness
http://www.zainea.com/soundandmusic.htm
I would check out the selections in:
loudness & dynamics
maybe also try some of the documents in mostly psychoacoustics

[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!

[sethjacquay]

Jeff,

Question, I have read the term VU time after time
in the this mastering book I am reading.
What, in the "name of Starbucks", does that mean?
Volume Unit?
Voltage Unit?
Voltran Unlimited?
Vulcan Unix?

Also, is there any standard at which you can measure not really
the loudness of the recording, but the level of the signal?

There really should be considering anyone can draw comparsions
using the AIFFs they create themselves and the AIFFs on mastered CDs.

[Jeff Pelletier]

Hey dude!

VU stands for volume unit.
*correction for last post:consumer operating level=-10dBV*

As I mentionned in my last post...the way to meter the level of a signal on a storage medium is by looking at those meters on your DAW. Unless the level of that signal never changes, you will have to "guesstimate" where that signal's level hangs out.

Just to clear up something for your last post...bitrate does not affect the minimum or maximum level at which you record signal (or range)...it only affects how many divisions there are between 0 level(-infinity) and 0dBfs(max number of 1s in the word).

[korektphool]

Hey peoples
Seth, i cant just test in my DAW what level the sound is at by looking at when it peaks, etc. I need a measurment, in numbers. And Jeff i kinda got wat u sed about the decibels. Is there any other unit of measurment for the volume? (decibels are the only i could think of). i know that the volume depends on many many variables but ill keep those all constant when trying to record and measure two or more samples.
And about building my own program that does wat i want, its almost impossible and i dont think ill buy hardware just for a science project. Just out of interest, why will anyone buy hardware for measuring something so trivial?
Raghav Kaushik
korektphool

[sethjacquay]

I was thinking you might be able use this plugin to measure
relative loudness by comparing song levels.

http://www.elementalaudio.com/products/ins...ctor/index.html

Could this be done, let me know what you think?

FYI - the plugin appears to be free!

[Dasa Soul]

Sethjacquay .will this plugin work on Garage band thanks

[destroyw]

bias-peak comes with a free plugin by Elemental Audio called "Inspector". Check it out.

http://www.elementalaudio.com/