Can I find average amplitude over a section of a track?

Special Interest Groups Audio Processing
1

Hello, Is there a way to find the average amplitude over a section of a track. I am wanting to quantity how much noise I have.
Thanks
Ron

2

We have a tool called ACX Check which will tell you the noise level, RMS (volume) and peak sound values. It’s normally used to make sure your sound work meets ACX AudioBook standards.

You need to have at least a half-second of silence in the show for ACX Check to work. I have a suggested sound clip format for testing and posting a sound clip on the forum, but it works on free-form performances, too.

http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html

http://wiki.audacityteam.org/wiki/Nyquist_Analyze_Plug-ins#ACX_Check

How to install plugins:
http://manual.audacityteam.org/man/customization.html

There’s also ways to measure audio noise manually, without the extra tool.

Let us know.

Koz

3

Hi - thank you for all the information about downloading plug-ins to help me find and adjust my RMS in Audacity. As a total novice, I’m stuck on the download. It asks me what application to open the download in. I tried Audacity, but it gives an error message. It won’t let me send it directly to Program Files Folder. what should I choose to get the plug ins into the right place?
thanks so much. Michael

4

“Nyquist” plug-ins are simple text files that contain a script in the Nyquist programming language.

Installation instructions for Nyquist plug-ins are here: https://wiki.audacityteam.org/wiki/Download_Nyquist_Plug-ins#install

5

thank you, steve! Everything installed and working. I pass after normalizing, but i fail on “exceeding noise floor of -60dB” If you can help me adjust that, I’m good to go! Appreciate your help. Michael

6

Home recordings routinely fail noise. Between home style microphones, bad announcing technique, noisy computers and noisy, echoey rooms, that’s the characteristic that fails most often.

It also has the most variations which is why it was left to its own instructions.

Record a test and post it on the forum. Content isn’t important Read the side of the milk carton, but do it in your normal announcing style. The test clip instructions don’t say so, but making a test too short isn’t useful, either. The silent segment is misleading. DO Not Move. We can hear your shirt and pants moving and chair creaking. It throws off the noise measurements.

http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html

Do not apply processing or corrections. We can’t take corrections out and a badly corrected clip doesn’t tell us anything.

Also include the equipment list. What kind of microphone do you have, how do you have it connected and to what.

Koz

7

normalizing

A note to be careful of your naming. “Normalizing” and “RMS Normalizing” are very different tools.

Are you following the ACX Mastering Suite 4?

Also there’s a note that selecting the whole timeline by clicking just above MUTE doesn’t work in Audacity 2.2.0. Double click the track itself.

Koz

8

Hey, Koz - you’re awesome! I’m passing the ACX test every time now. Thanks! Here’s the next weird thing…so that I can send off the audition, I save it as an MP3 file. But when I try to play the file independently, not through Audacity, (it shows 1.7MB, and dot is clearly moving for the 78 seconds of the clip ) there is no sound! Not in my headphones, or on my computer.

I sent off my first audition using that MP3 file, and the confirmation example had no sound either. OUCH! What have i done wrong this time???

Thanks again… M
BTW, I’m using version 2.1.3, and an audio technica 2020USB mic…

9

Oops, sorry…I figured it out… I have to unplug the mic to get sound. Duhhh. Ok. All good. Thanks again. I’ll get back to you at my next impasse… M