I’m narrating my own book, and audio.com says that the uploaded file must measure between -23dB and -18dB RMS. I have no idea what this means or how to find out if the file I’m creating meets this standard. Please help.

If we assume they’re using the same audiobook settings as ACX…


Audacity has an add-on tool that can automatically display all three (and more) of the critical sound readings—including RMS. This can be insanely handy because it lets you manage the sound quality at home without ping-pong shipping files around.

This should still be current:



There are ways to measure the sound quality without this tool, but it’s a page of click this and click that instructions. The measurement tool is much better.

Let us know where you get stuck.


Once you get it installed, it appears as Analyze > ACX Check.

Attached: I analyzed a sound test I had on the machine. Turns out the peak and RMS are OK, but the background noise is too high—first three readings.

So it fails ACX Check.

Zero is the maximum volume you can have and the numbers get higher as the volume goes down.

0dB Maximum.
-3dB ACX Audiobook volume peaks
-18dB to -23dB RMS Loudness range.
-60dB Loudest possible noise when you stop talking. My clip has -59dB noise which is too loud.

Screen Shot 2016-05-10 at 7.28.57 PM.png

Thank you so much.

Once you get readings, we can recommend new settings. It’s possible to go nuts. Fix RMS and that throws the peaks off. Fix the peaks and the noise gets worse…

Let us know.