What computer operating system is your Premiere Elements 12 running on? And, have you updated 12 to 12.1 using an opened project's Help Menu/Update? If not, please do so.
Open the project involved, go to the Expert workspace, Window Menu/Audio Meters and click on Audio Meter. Leave the Audio Meter opened as you play back the Timeline and evaluate the volume of the sound.
Was the sound in this project only from narration? Did you also have sound from the Soundtrack as well as numbered Audio Track(s)? Did you apply the SmartMix feature to your Timeline?
What was the file size and duration of the video upload to YouTube at the YouTube web site?
Let us start here and then decide what next.
Add On...You said that you could hear the narration in Premiere Elements project but not in play back of your video which was uploaded to YouTube at the YouTube web site.
But what about the narration sound for the file that was saved to the computer hard drive before the upload to YouTube? Sound or no sound at the computer hard drive level?
Thank you for responding. I am not sure the exact model of the computer,
but it is an acer PC. I will consider updating. In the audio meter, the
sound increased. Only the narration audio was muted when uploaded to
youtube and not the soundtrack and other audio tracks. I am not sure what
the file size is, how do you determine it?
On Tue, Dec 9, 2014 at 5:25 PM, A.T. Romano <firstname.lastname@example.org>
Sorry for the delayed response. I lost sight of your thread.
Does the problem still exist with the loss of narration in the upload to YouTube?
You can determine the file size of your upload by noting the file size displayed with its thumbnail at its hard drive save location just before you upload the file to YouTube at the YouTube web site.
Also, you can get at the file size by looking at the file size estimate in Premiere Elements export area where you create the file that
will be uploaded to YouTube at the YouTube web site.
Was this narration created in Premiere Elements with the program's Narration Tool or created in a program such as Audacity and then the Audacity narration
imported into Premiere Elements with Premiere Elements's Add Media/Files and Folders?