I am sorry, but what I could suggest is that we start from scratch. Because only that way can we talk about the same file. Delete ALL the tests you did so far and re-record this Peter Piper sentence. Name it test_flowerpower_new1, for example.
> I'll give you a helpful tool named ReplayGain, to check your volume before exporting:
this should help you to know by how much you need to amplify or decrease your volume to get to 89 dB. Try it out before you export.The easiest way is to install an extra plugin in Audacity that will tell you by how much the recording needs to be amplified to reach the desired volume of 89 dB.
Replay Gain plugin for Audacity: - http://forum.audacityteam.org/download/file.php?id=4668
1. Save the file to your computer - your desktop or somewhere where you can easily find it.
2. Now browse to the folder in which Audacity is installed. It's probably in C:\Program Files\Audacity) and then open the Plug-Ins folder.
3. Drag the file you saved into the Plug-Ins folder.
4. When next you start up Audacity, you will be able to select the whole recording (Ctrl+A on Windows), then go to Analyze | ReplayGain, and it'll tell you how much to amplify your file to get to about 89 dB.
> Another helpful tool is Checker, you can use that to check your finished mp3 file and it will tell you if there are issues still.
Let's try anew, if this can help you.