Sound Level Changes

[jevans]

I have sometimes noticed an unexpected change in sound levels when preparing shows.  For example I have a slide list with the required slides and have added voice clips to various slides.  Then I add a second background music track.  When you play the show back, the level of the background music suddenly seems to drop when a voice clip plays, even although I have not changed the level.

I attach a zip file with and example.  If you play the section, you should hear the music level drop which the voice appears.  If you mute the voice track, the music level appears to remain unchanged.  If the voice track is not muted, the music sound level also seems to remain reduced after the voice track finishes.  Anyone else noticed this or have any idea what is happening?

Sound_Level_Test.zip

[Lin Evans]

Hi Jeff,

I can't really tell that the actual sound level of the background has changed because the voice over is much louder and tends to mask the background audio, but what about the audio waveform for the backgoround music - is there any perceptual visual change in that volume level? Are the numbers for the background audio in terms of volume identical before, during and after the voice clip?

One way to perhaps better test this would be to add silent audio clips to a couple pictures so all you actually hear is the background audio but the mp3 audio clips for each slide are still being actuated. Then it would be easier to discern whether there were a "real" versus "perceptual" difference in the background sound track?

Best regards,

Lin

 

[davegee]

Hi Jeff,

If the two audio files used in the example were available for independent testing it might be more meaning ful than listening to the exe of your project.

[denisb]

Hi,

in French a possible explanation:  http://www.diapositif.net/forum/viewtopic.php?f=9&t=39710

 

As I have not an English Windows available, difficult to translate. See the figures and try to get the same thing. In French it is called" égalisation loudness" which is perhaps ticked in your case. May be it is the translation of Loudness equalization

 

Denis

[jevans]

Thanks to all for your replies.  I apologise for attaching the wrong zip file.  I meant to attach the project zip so that you could unzip and look at the project.  So the correct project zip is attached.  Unzip this an run the pte file in the "Timeline" window.  First with both audio tracks enabled.  Listen to the music track as the speech track begins. There appears to be a sudden drop in the volume of the music track and this lower level continues after the speech track finishes.  No mute the speech track and try again.  The music track volume remains unchanged.

I have tried this using both wav and mp3 files and the effect occurs with both file types.

Dave :  The sound files are included in the project zip.

Lin : There is no perceptual change in the music track waveform.  Tried with a "silent" speech track and the reduction in volume of the music tract does not occur.

Denis : Do not completely understand the French but think that this is perhaps not relevant.

Thanks gentlemen for your assistance.

Regards

Jeff

NOTE : The standard PTE zip file will not upload with an error message saying that it is more than 3.1Mb which t is not.  So the attached zip file is a standard winzip version.

 

Sound Test Files.zip

[davegee]

Jeff,

In the original EXE the effect that you speak of is quite noticeable because it is "burned in".

However, in the Project File that you posted there is no discernible drop in level of the BG music when then the Voice Clip plays. Just in case  I created an EXE in Zip to see if that did it but still no drop in level. Denis's theory is plausible but my W10 interface looks nothing like his and I could not find the switch that he mentioned.

Whatever is causing it, I suggest the PTE is not the culprit here?

 

[Lin Evans]

Hi Dave,

I think the situation Denis refers to has to do with a specific sound card brand if I read the forum correctly. If you have a different audio card, you probably won't see the same switch. The reason I suggested Jeff create a "silent" audio clip insert was to see if it was the file or perhaps something in the audio itself which was causing the problem. The fact that a silent mp3 results in no drop in background audio levels pretty much rules out PTE as the source of the problem I think.

Best regards,

Lin

[denisb]

I am sure that if I thicked the Loudness equalizaton, i ear changes in music volume of your project.

 

a dell audio program could cause the same thing:

Denis

[davegee]

1 hour ago, Lin Evans said:

Hi Dave,

I think the situation Denis refers to has to do with a specific sound card brand if I read the forum correctly. If you have a different audio card, you probably won't see the same switch. The reason I suggested Jeff create a "silent" audio clip insert was to see if it was the file or perhaps something in the audio itself which was causing the problem. The fact that a silent mp3 results in no drop in background audio levels pretty much rules out PTE as the source of the problem I think.

Best regards,

Lin

I'm pretty sure that the project file that Jeff supplied does not cause a dip in volume on my laptop and that to my mind pretty much rules out PTE as the cause. But who knows .......

 

DG

[Lin Evans]

Yes, it seems to me that by creating a silent mp3 for the audio clip on the slide if there was no change in the audio volume of the background, it would be highly unlikely that PTE was responsible. I can't detect any change in volume on either of my two systems "Win XP and Win 8.1" with different sound systems so I would guess it's something endemic to Jeff's system.

It's difficult to suss out all the permutations and possibilities, but I agree - I think we can rule out PTE as the cause.

L